sched/debug: Don't dump sched debug info in SysRq-W

sched/debug: Don't dump sched debug info in SysRq-W

sysrq_sched_debug_show() can dump a lot of information.  Don't print out
all that if we're just trying to get a list of blocked tasks (SysRq-W).
The information is still accessible with SysRq-T.

Signed-off-by: Rabin Vincent <rabinv@axis.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1459777322-30902-1-git-send-email-rabin.vincent@axis.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>