automated: linux: signaltest: fix indentation

Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
diff --git a/automated/linux/signaltest/signaltest.sh b/automated/linux/signaltest/signaltest.sh
index e7db4f3..fc044b0 100755
--- a/automated/linux/signaltest/signaltest.sh
+++ b/automated/linux/signaltest/signaltest.sh
@@ -22,8 +22,8 @@
     case "${opt}" in
         p) PRIORITY="${OPTARG}" ;;
         t) THREADS="${OPTARG}" ;;
-	D) DURATION="${OPTARG}" ;;
-	w) BACKGROUND_CMD="${OPTARG}" ;;
+        D) DURATION="${OPTARG}" ;;
+        w) BACKGROUND_CMD="${OPTARG}" ;;
         *) usage ;;
     esac
 done