Use require_command() so that the test will return SKIP (4) when a
required command is not present.

Before:

 # ./traceroute.sh
 SKIP: Could not run IPV6 test without traceroute6
 SKIP: Could not run IPV4 test without traceroute
 $ echo $?
 0

After:

 # ./traceroute.sh
 TEST: traceroute6 not installed                                    [SKIP]
 $ echo $?
 4

Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 tools/testing/selftests/net/traceroute.sh | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/net/traceroute.sh b/tools/testing/selftests/net/traceroute.sh
index 46cb37e124ce..1ac91eebd16f 100755
--- a/tools/testing/selftests/net/traceroute.sh
+++ b/tools/testing/selftests/net/traceroute.sh
@@ -181,11 +181,6 @@ setup_traceroute6()
 
 run_traceroute6()
 {
-	if [ ! -x "$(command -v traceroute6)" ]; then
-		echo "SKIP: Could not run IPV6 test without traceroute6"
-		return
-	fi
-
 	setup_traceroute6
 
 	RET=0
@@ -249,11 +244,6 @@ setup_traceroute()
 
 run_traceroute()
 {
-	if [ ! -x "$(command -v traceroute)" ]; then
-		echo "SKIP: Could not run IPV4 test without traceroute"
-		return
-	fi
-
 	setup_traceroute
 
 	RET=0
@@ -287,6 +277,9 @@ do
 	esac
 done
 
+require_command traceroute6
+require_command traceroute
+
 run_tests
 
 exit "${EXIT_STATUS}"
-- 
2.51.0