LU-5332 hsm: Release XATTR lock on exiting

LU-5332 hsm: Release XATTR lock on exiting

This should be a typo where it should jump to out_unlock instead of
out_ucred.

This is a backport to b2_5.

Lustre-change: http://review.whamcloud.com/11083
Lustre-commit: 393350b37cae30efc03ffc076c77e390999c2a2d

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Signed-off-by: James Nunez <james.a.nunez@intel.com>
Change-Id: I03242e40f7e33a115934081375be7c86044fa254
Reviewed-on: http://review.whamcloud.com/11215
Tested-by: Jenkins
Reviewed-by: frank zago <fzago@cray.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>