[PATCH] selftests: kselftest_deps: fix l5_test() empty variable

[Lu Dai]

In the function l5_test(), variable $tests is empty when there is no .mk
file in the subsystem to be tested. It causes the following grep operation
stuck.

This fix check the variable $tests, return when it is empty.

Signed-off-by: Lu Dai <dai.lu@xxxxxxxxxxx>
---
 tools/testing/selftests/kselftest_deps.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/kselftest_deps.sh b/tools/testing/selftests/kselftest_deps.sh
index de59cc8f03c3..487e49fdf2a6 100755
--- a/tools/testing/selftests/kselftest_deps.sh
+++ b/tools/testing/selftests/kselftest_deps.sh
@@ -244,6 +244,7 @@ l4_test()
 l5_test()
 {
 	tests=$(find $(dirname "$test") -type f -name "*.mk")
+	[[ -z "${tests// }" ]] && return
 	test_libs=$(grep "^IOURING_EXTRA_LIBS +\?=" $tests | \
 			cut -d "=" -f 2)
 
-- 
2.39.2