printk: do not include interrupt.h

A trivial cosmetic change: interrupt.h header is redundant since commit
6b898c0 ("console: use might_sleep in console_lock").

Link: http://lkml.kernel.org/r/20160620132847.21930-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/printk/printk.c

@@ -26,7 +26,6 @@
 #include <linux/nmi.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/interrupt.h>			/* For in_interrupt() */
 #include <linux/delay.h>
 #include <linux/smp.h>
 #include <linux/security.h>