PM: sleep: Refine error message in try_to_freeze_tasks()

A previous change amended try_to_freeze_tasks() with the "what"
variable pointing to a string describing the group of tasks subject to
the freezing which may be used in the error message in there too, so
make that happen.

Accordingly, update sleepgraph.py to catch the modified error message
as appropriate.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>

kernel/power/process.c

@@ -86,8 +86,8 @@ static int try_to_freeze_tasks(bool user_only)
 	elapsed_msecs = ktime_to_ms(elapsed);
 
 	if (todo) {
-		pr_err("Freezing of tasks %s after %d.%03d seconds "
-		       "(%d tasks refusing to freeze, wq_busy=%d):\n",
+		pr_err("Freezing %s %s after %d.%03d seconds "
+		       "(%d tasks refusing to freeze, wq_busy=%d):\n", what,
 		       wakeup ? "aborted" : "failed",
 		       elapsed_msecs / 1000, elapsed_msecs % 1000,
 		       todo - wq_busy, wq_busy);

tools/power/pm-graph/sleepgraph.py

@@ -1462,7 +1462,7 @@ class Data:
 		'TIMEOUT' : r'(?i).*\bTIMEOUT\b.*',
 		'ABORT'   : r'(?i).*\bABORT\b.*',
 		'IRQ'     : r'.*\bgenirq: .*',
-		'TASKFAIL': r'.*Freezing of tasks *.*',
+		'TASKFAIL': r'.*Freezing .*after *.*',
 		'ACPI'    : r'.*\bACPI *(?P<b>[A-Za-z]*) *Error[: ].*',
 		'DISKFULL': r'.*\bNo space left on device.*',
 		'USBERR'  : r'.*usb .*device .*, error [0-9-]*',