xfs: remove redundant user buffer count checks at xfs_bulkstat

From: Jie Liu <jeff.liu@oracle.com>

Remove the redundant user buffer and count checks as it has already
been validated at xfs_ioc_bulkstat().

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_itable.c

@@ -230,9 +230,7 @@ xfs_bulkstat(
 		*ubcountp = 0;
 		return 0;
 	}
-	if (!ubcountp || *ubcountp <= 0) {
-		return -EINVAL;
-	}
+
 	ubcount = *ubcountp; /* statstruct's */
 	ubleft = ubcount * statstruct_size; /* bytes */
 	*ubcountp = ubelem = 0;