automated: use create_out_dir where appropriate

Change-Id: I10181a7d1ebc53491085d80d67f0cd8f9e43071d
Signed-off-by: Daniel Díaz <daniel.diaz@linaro.org>
diff --git a/automated/linux/blogbench/blogbench.sh b/automated/linux/blogbench/blogbench.sh
index b07d9f9..a09e750 100755
--- a/automated/linux/blogbench/blogbench.sh
+++ b/automated/linux/blogbench/blogbench.sh
@@ -21,8 +21,7 @@
 done
 
 ! check_root && error_msg "You need to be root to run this script."
-[ -d "${OUTPUT}" ] && mv "${OUTPUT}" "${OUTPUT}_$(date +%Y%m%d%H%M%S)"
-mkdir -p "${OUTPUT}"
+create_out_dir "${OUTPUT}"
 
 # Set the directory for blogbench test.
 if [ -n "${PARTITION}" ]; then