staging: lustre: ldlm: refine LU-2665 patch for POSIX compliance

Follow-on to patch introduced to fix LU-2665 ticket (Gerrit
Change at http://review.whamcloud.com/6415 with Change-Id:
I8faa331712abeadee46eabe111ee1c23a05840d5).
Original patch introduced regressions against POSIX test suite
(fcntl.18/fcntl.35 tests in LSB-VSX POSIX test suite at
http://www.opengroup.org/testing/linux-test/lsb-vsx.html),
so the idea is to only resend F_UNLCKs to have both LU-2665 bug
and POSIX test suite happy.
Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3701
Reviewed-on: http://review.whamcloud.com/7453Reviewed-by: Bobi Jam <bobijam@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/mdc/mdc_locks.c

@@ -869,7 +869,9 @@ int mdc_enqueue(struct obd_export *exp, struct ldlm_enqueue_info *einfo,
 		 * (explicits or automatically generated by Kernel to clean
 		 * current FLocks upon exit) that can't be trashed
 		 */
-		if ((rc == -EINTR) || (rc == -ETIMEDOUT))
+		if (((rc == -EINTR) || (rc == -ETIMEDOUT)) &&
+		    (einfo->ei_type == LDLM_FLOCK) &&
+		    (einfo->ei_mode == LCK_NL))
 			goto resend;
 		return rc;
 	}