Use defined random service name

Regression/bz1490927-vim-dumps-core-when-system-reboots/runtest.sh

@@ -32,6 +32,7 @@ PACKAGE="vim-enhanced"
 REPRODUCER="$PWD/reproducer.sh"
 SSH_PRIVKEY="/root/.ssh/id_ed25519"
 SSH_PUBKEY="/root/.ssh/id_ed25519.pub"
+SERVICE_NAME="run-$RANDOM"
 
 rlJournalStart
     rlPhaseStartSetup
@@ -52,9 +53,9 @@ for i in {0..9}; do
         TEST_DIR="$(mktemp -d $PWD/testdirXXX)"
 
         # Run the reproducer under its own slice to not kill our current one
-        rlRun "systemd-run -r --slice $SLICE /bin/bash $REPRODUCER $TEST_DIR 2>&1 | tee $LOG_FILE"
+        rlRun "systemd-run -r --slice $SLICE --unit $SERVICE_NAME /bin/bash $REPRODUCER $TEST_DIR 2>&1 | tee $LOG_FILE"
         # Now check if the reproducer was started successfully
-        SERVICE="$(grep -Eo "(run-[0-9a-zA-Z]*.service)" $LOG_FILE)"
+        SERVICE="$(grep -Eo "($SERVICE_NAME.service)" $LOG_FILE)"
         if [[ -z "$SERVICE" ]]; then
             rlFail "Failed to start the reproducer via systemd-run"
         else