selftests: ublk: fix test_stripe_04

Commit 57ed58c ("selftests: ublk: enable zero copy for stripe target")
added test entry of test_stripe_04, but forgot to add the test script.

So fix the test by adding the script file.

Reported-by: Uday Shankar <ushankar@purestorage.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Uday Shankar <ushankar@purestorage.com>
Link: https://lore.kernel.org/r/20250404001849.1443064-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

tools/testing/selftests/ublk/test_stripe_04.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+. "$(cd "$(dirname "$0")" && pwd)"/test_common.sh
+
+TID="stripe_04"
+ERR_CODE=0
+
+_prep_test "stripe" "mkfs & mount & umount on zero copy"
+
+backfile_0=$(_create_backfile 256M)
+backfile_1=$(_create_backfile 256M)
+dev_id=$(_add_ublk_dev -t stripe -z -q 2 "$backfile_0" "$backfile_1")
+_check_add_dev $TID $? "$backfile_0" "$backfile_1"
+
+_mkfs_mount_test /dev/ublkb"${dev_id}"
+ERR_CODE=$?
+
+_cleanup_test "stripe"
+
+_remove_backfile "$backfile_0"
+_remove_backfile "$backfile_1"
+
+_show_result $TID $ERR_CODE