btrfs: ioctl: reorder exclusive op check in RM_DEV

Move the op exclusivity check before the other code (same as in
ADD_DEV).

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2016-05-04 14:10:47 +02:00 • committed by David Sterba
commit 58d7bbf81f