sched/debug: Use symbolic names for task state constants

include/trace/events/sched.h includes <linux/sched.h> (via
<linux/sched/numa_balancing.h>) and so knows about the TASK_* constants
used to interpret .prev_state. So instead of duplicating the magic
numbers make use of the defined macros to ease understanding the
mapping from state bits to letters which isn't completely intuitive for
an outsider.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel@pengutronix.de
Link: http://lkml.kernel.org/r/20180905093636.24068-1-u.kleine-koenig@pengutronix.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

include/trace/events/sched.h

@@ -159,9 +159,14 @@ TRACE_EVENT(sched_switch,
 
 		(__entry->prev_state & (TASK_REPORT_MAX - 1)) ?
 		  __print_flags(__entry->prev_state & (TASK_REPORT_MAX - 1), "|",
-				{ 0x01, "S" }, { 0x02, "D" }, { 0x04, "T" },
-				{ 0x08, "t" }, { 0x10, "X" }, { 0x20, "Z" },
-				{ 0x40, "P" }, { 0x80, "I" }) :
+				{ TASK_INTERRUPTIBLE, "S" },
+				{ TASK_UNINTERRUPTIBLE, "D" },
+				{ __TASK_STOPPED, "T" },
+				{ __TASK_TRACED, "t" },
+				{ EXIT_DEAD, "X" },
+				{ EXIT_ZOMBIE, "Z" },
+				{ TASK_PARKED, "P" },
+				{ TASK_DEAD, "I" }) :
 		  "R",
 
 		__entry->prev_state & TASK_REPORT_MAX ? "+" : "",