tracing/histogram: Wrap remaining shell snippets in code blocks

Most shell command snippets (echo/cat) and their output are already in
literal code blocks. However a few still isn't wrapped, in which the
htmldocs output is ugly.

Wrap the remaining unwrapped snippets, while also fix recent kernel test
robot warnings.

Link: https://lore.kernel.org/linux-trace-kernel/20230129031402.47420-1-bagasdotme@gmail.com

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/linux-doc/202301290253.LU5yIxcJ-lkp@intel.com/
Fixes: 88238513 ("tracing/histogram: Document variable stacktrace")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Documentation/trace/histogram.rst

@@ -1864,7 +1864,7 @@ A histogram can now be defined for the new synthetic event::
 The above shows the latency "lat" in a power of 2 grouping.
 
 Like any other event, once a histogram is enabled for the event, the
-output can be displayed by reading the event's 'hist' file.
+output can be displayed by reading the event's 'hist' file::
 
   # cat /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/hist
 
@@ -1911,7 +1911,7 @@ output can be displayed by reading the event's 'hist' file.
 
 
 The latency values can also be grouped linearly by a given size with
-the ".buckets" modifier and specify a size (in this case groups of 10).
+the ".buckets" modifier and specify a size (in this case groups of 10)::
 
   # echo 'hist:keys=pid,prio,lat.buckets=10:sort=lat' >> \
         /sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
@@ -1945,7 +1945,7 @@ the ".buckets" modifier and specify a size (in this case groups of 10).
 
 To save stacktraces, create a synthetic event with a field of type "unsigned long[]"
 or even just "long[]". For example, to see how long a task is blocked in an
-uninterruptible state:
+uninterruptible state::
 
   # cd /sys/kernel/tracing
   # echo 's:block_lat pid_t pid; u64 delta; unsigned long[] stack;' > dynamic_events
@@ -1990,7 +1990,8 @@ uninterruptible state:
   => kthread+0xe9/0x110
   => ret_from_fork+0x2c/0x50
 
-A synthetic event that has a stacktrace field may use it as a key in histogram:
+A synthetic event that has a stacktrace field may use it as a key in
+histogram::
 
   # echo 'hist:delta.buckets=100,stack.stacktrace:sort=delta' > events/synthetic/block_lat/trigger
   # cat events/synthetic/block_lat/hist
@@ -2183,7 +2184,7 @@ The following commonly-used handler.action pairs are available:
               wakeup_new_test($testpid) if comm=="cyclictest"' >> \
               /sys/kernel/debug/tracing/events/sched/sched_wakeup_new/trigger
 
-    Or, equivalently, using the 'trace' keyword syntax:
+    Or, equivalently, using the 'trace' keyword syntax::
 
       # echo 'hist:keys=$testpid:testpid=pid:onmatch(sched.sched_wakeup_new).\
               trace(wakeup_new_test,$testpid) if comm=="cyclictest"' >> \
@@ -2320,7 +2321,7 @@ The following commonly-used handler.action pairs are available:
     resulting latency, stored in wakeup_lat, exceeds the current
     maximum latency, a snapshot is taken.  As part of the setup, all
     the scheduler events are also enabled, which are the events that
-    will show up in the snapshot when it is taken at some point:
+    will show up in the snapshot when it is taken at some point::
 
       # echo 1 > /sys/kernel/debug/tracing/events/sched/enable
 
@@ -2339,7 +2340,7 @@ The following commonly-used handler.action pairs are available:
     following the rest of the fields.
 
     If a snapshot was taken, there is also a message indicating that,
-    along with the value and event that triggered the global maximum:
+    along with the value and event that triggered the global maximum::
 
       # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
         { next_pid:       2101 } hitcount:        200
@@ -2439,7 +2440,7 @@ The following commonly-used handler.action pairs are available:
     $cwnd variable.  If the value has changed, a snapshot is taken.
     As part of the setup, all the scheduler and tcp events are also
     enabled, which are the events that will show up in the snapshot
-    when it is taken at some point:
+    when it is taken at some point::
 
       # echo 1 > /sys/kernel/debug/tracing/events/sched/enable
       # echo 1 > /sys/kernel/debug/tracing/events/tcp/enable
@@ -2470,7 +2471,7 @@ The following commonly-used handler.action pairs are available:
       { dport:        443 } hitcount:        211
 	changed:         10  snd_wnd:      26960  srtt:      17379  rcv_wnd:      28800
 
-    Snapshot taken (see tracing/snapshot).  Details::
+      Snapshot taken (see tracing/snapshot).  Details:
 
           triggering value { onchange($cwnd) }:         10
           triggered by event with key: { dport:         80 }