The comment helpfully explains why hardirq.h is included, but since
commit 2d4b8473 ("hardirq: Split preempt count mask definitions")
in_interrupt() has been provided by preempt_mask.h.  Use that instead,
saving around 40 lines in the generated dependency file.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>