[PATCH] oprofile: fix potential deadlock on oprofilefs_lock

nmi_cpu_setup() is called from hardirq context and acquires oprofilefs_lock.
alloc_event_buffer() and oprofilefs_ulong_from_user() acquire this lock
without disabling irqs, which could deadlock.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>