sched/debug: Fix per-task line continuation for console output

When the SEQ_printf() macro prints to the console, it runs a simple
printk() without KERN_CONT "continued" line printing.  The result of
this is oddly wrapped task info, for example:

  % echo t > /proc/sysrq-trigger
  % dmesg
  ...
  runnable tasks:
  ...
  [   29.608611]  I
  [   29.608613]       rcu_sched     8      3252.013846      4087   120
  [   29.608614]         0.000000        29.090111         0.000000
  [   29.608615]  0 0
  [   29.608616]  /

Modify SEQ_printf to use pr_cont() for expected one-line results:

  % echo t > /proc/sysrq-trigger
  % dmesg
  ...
  runnable tasks:
  ...
  [  106.716329]  S        cpuhp/5    37      2006.315026        14   120         0.000000         0.496893         0.000000 0 0 /
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1521484555-8620-2-git-send-email-joe.lawrence@redhat.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/debug.c

@@ -32,7 +32,7 @@ static DEFINE_SPINLOCK(sched_debug_lock);
 	if (m)					\
 		seq_printf(m, x);		\
 	else					\
-		printk(x);			\
+		pr_cont(x);			\
  } while (0)
 
 /*