The situation len = 0 and absolute = false need to be handled

Add a return case for len == 0 and absolute == false

Change-Id: Ia36bd67ced6abbe7234eb7e485c1a2d8bd928ffe
Signed-off-by: Benoit Fradin <benoit.fradin@intel.com>
diff --git a/ext4_utils/make_ext4fs.c b/ext4_utils/make_ext4fs.c
index b9a24b8..f164883 100644
--- a/ext4_utils/make_ext4fs.c
+++ b/ext4_utils/make_ext4fs.c
@@ -427,8 +427,11 @@
 	int newlen = len;
 	char *ptr;
 
-	if (len == 0 && absolute) {
-		return strdup("/");
+	if (len == 0) {
+		if (absolute)
+			return strdup("/");
+		else
+			return strdup("");
 	}
 
 	if (str[0] != '/' && absolute) {