LU-8735 llite: Return -ERESTARTSYS in range_lock()

LU-8735 llite: Return -ERESTARTSYS in range_lock()

If we return -ERESTARTSYS rather than -EINTR then the syscall can be
retried rather than failing with -EINTR.

Signed-off-by: Chris Horn <hornc@cray.com>
Change-Id: I20d1a552448e567f0400a14a71a00d0d25a9164d
Reviewed-on: https://review.whamcloud.com/23259
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>