LU-11429 mdt: rename mdt_remote_permission

LU-11429 mdt: rename mdt_remote_permission

Rename mdt_remote_permission() to mdt_remote_dir_permission() and
mdt_remote_permission_check() to mdt_remote_dir_permission_check()
to match the "mdt_remote_dir" and "mdt_remote_dir_gid" proc tunable
names.

Test-Parameters: trivial
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I3336260b3fdc0a1ab3b12a7e2c4722c7a63ebbe5
Reviewed-on: https://review.whamcloud.com/33247
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Ben Evans <bevans@cray.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>