Staging: lustre: Removed space prohibited

WARNING:  space prohibited before that '--'
Removed space prohibited. That was found by running checkpatch.
Signed-off-by: Melike Yurtoglu <aysemelikeyurtoglu@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/ptlrpc/layout.c

@@ -1839,7 +1839,7 @@ static int __req_capsule_offset(const struct req_capsule *pill,
 	LASSERTF(offset > 0, "%s:%s, off=%d, loc=%d\n",
 			    pill->rc_fmt->rf_name,
 			    field->rmf_name, offset, loc);
-	offset --;
+	offset--;
 
 	LASSERT(0 <= offset && offset < REQ_MAX_FIELD_NR);
 	return offset;