fstab-util: use pointer returned by startswith()

src/shared/fstab-util.c

@@ -305,19 +305,25 @@ static char *tag_to_udev_node(const char *tagvalue, const char *by) {
 }
 
 char *fstab_node_to_udev_node(const char *p) {
+        const char *q;
+
         assert(p);
 
-        if (startswith(p, "LABEL="))
-                return tag_to_udev_node(p+6, "label");
+        q = startswith(p, "LABEL=");
+        if (q)
+                return tag_to_udev_node(q, "label");
 
-        if (startswith(p, "UUID="))
-                return tag_to_udev_node(p+5, "uuid");
+        q = startswith(p, "UUID=");
+        if (q)
+                return tag_to_udev_node(q, "uuid");
 
-        if (startswith(p, "PARTUUID="))
-                return tag_to_udev_node(p+9, "partuuid");
+        q = startswith(p, "PARTUUID=");
+        if (q)
+                return tag_to_udev_node(q, "partuuid");
 
-        if (startswith(p, "PARTLABEL="))
-                return tag_to_udev_node(p+10, "partlabel");
+        q = startswith(p, "PARTLABEL=");
+        if (q)
+                return tag_to_udev_node(q, "partlabel");
 
         return strdup(p);
 }