hrtimer: fix section mismatch

Fix section mismatch in hrtimer.c:

WARNING: vmlinux.o(.text+0x50c61): Section mismatch: reference to .init.text: (between 'hrtimer_cpu_notify' and 'down_read_trylock')

Noticed by Johannes Berg and confirmed by Sam Ravnborg.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@akpm@linux-foundation.org>