selftests: bpf: notification about privilege required to run test_lwt_seg6local.sh testing script

This test needs root privilege for it's successful execution.

This patch is atleast used to notify the user about the privilege
the script demands for the  smooth execution of the test.
Signed-off-by: NJeffrin Jose T (Rajagiri SET) <ahiliation@gmail.com>
Acked-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

tools/testing/selftests/bpf/test_lwt_seg6local.sh

@@ -21,6 +21,15 @@
 # An UDP datagram is sent from fb00::1 to fb00::6. The test succeeds if this
 # datagram can be read on NS6 when binding to fb00::6.
 
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+msg="skip all tests:"
+if [ $UID != 0 ]; then
+	echo $msg please run this as root >&2
+	exit $ksft_skip
+fi
+
 TMP_FILE="/tmp/selftest_lwt_seg6local.txt"
 
 cleanup()