btrfs: drop gfp_t from lock_extent

 lock_extent and unlock_extent are always called with GFP_NOFS, drop the
 argument and use GFP_NOFS consistently.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>

diff --cc fs/btrfs/compression.c
Simple merge

diff --cc fs/btrfs/disk-io.c
Simple merge

diff --cc fs/btrfs/extent_io.c
Simple merge

diff --cc fs/btrfs/extent_io.h
Simple merge

diff --cc fs/btrfs/file.c
Simple merge

diff --cc fs/btrfs/free-space-cache.c
Simple merge

diff --cc fs/btrfs/inode.c
Simple merge

diff --cc fs/btrfs/ioctl.c
Simple merge

diff --cc fs/btrfs/relocation.c
Simple merge