blk: fix wrong idr_pre_get() error check in loop.c
blk: fix wrong idr_pre_get() error check in loop.c

The idr_pre_get() function never returns a value < 0.  It returns 0 (no
memory) or 1 (OK).

Reported-by: Silva Paulo <fe9a1b16845ea4b1355afe721608465c6027dc67@yahoo.com>
[ Rewrote Silva's patch, but attributing it to Silva anyway  - Linus ]
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs