tracing: fix cut and paste macro error

In case a module uses the TRACE_EVENT macro for creating automated
events in ftrace, it may choose to use a different file name
than the defined system name, or choose to use a different path than
the default "include/trace/events" include path.

If this is done, then before including trace/define_trace.h the
header would define either "TRACE_INCLUDE_FILE" for the file
name or "TRACE_INCLUDE_PATH" for the include path.

If it does not define these, then the define_trace.h defines them
instead. If define trace defines them, then define_trace.h should
also undefine them before exiting. To do this a macro is used
to note this:

 #ifndef TRACE_INCLUDE_FILE
 # define TRACE_INCLUDE_FILE TRACE_SYSTEM
 # define UNDEF_TRACE_INCLUDE_FILE
 #endif

[...]

 #ifdef UNDEF_TRACE_INCLUDE_FILE
 # undef TRACE_INCLUDE_FILE
 # undef UNDEF_TRACE_INCLUDE_FILE
 #endif

The UNDEF_TRACE_INCLUDE_FILE acts as a CPP variable to know to undef
the TRACE_INCLUDE_FILE before leaving define_trace.h.

Unfortunately, due to cut and paste errors, the macros between
FILE and PATH got mixed up.

[ Impact: undef TRACE_INCLUDE_FILE and/or TRACE_INCLUDE_PATH when needed ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

include/trace/define_trace.h

@@ -44,7 +44,7 @@
 
 #ifndef TRACE_INCLUDE_PATH
 # define __TRACE_INCLUDE(system) <trace/events/system.h>
-# define UNDEF_TRACE_INCLUDE_FILE
+# define UNDEF_TRACE_INCLUDE_PATH
 #else
 # define __TRACE_INCLUDE(system) __stringify(TRACE_INCLUDE_PATH/system.h)
 #endif
@@ -64,13 +64,13 @@
 
 /* Only undef what we defined in this file */
 #ifdef UNDEF_TRACE_INCLUDE_FILE
-# undef TRACE_INCLUDE_PATH
+# undef TRACE_INCLUDE_FILE
 # undef UNDEF_TRACE_INCLUDE_FILE
 #endif
 
-#ifdef UNDEF_TRACE_INCLUDE_FILE
+#ifdef UNDEF_TRACE_INCLUDE_PATH
 # undef TRACE_INCLUDE_PATH
-# undef UNDEF_TRACE_INCLUDE_FILE
+# undef UNDEF_TRACE_INCLUDE_PATH
 #endif
 
 /* We may be processing more files */