path BUGFIX handle 0 path count

It occurs in a specific case when
called from lyd_new_path2.
diff --git a/src/path.c b/src/path.c
index 3f4ad18..e1dedef 100644
--- a/src/path.c
+++ b/src/path.c
@@ -912,7 +912,7 @@
         struct lyd_node **match)
 {
     LY_ARRAY_COUNT_TYPE u;
-    struct lyd_node *prev_node = NULL, *node, *target;
+    struct lyd_node *prev_node = NULL, *node = NULL, *target;
     uint64_t pos;
 
     assert(path && start);