libyang MAINTENANCE uninitializes variables in optimized code

Silent (probably false positive, but who knows with optimizations)
compiler's warnings (mostly) about uninitialized variables when being
compiled as Release build type.
diff --git a/src/schema_compile_amend.c b/src/schema_compile_amend.c
index f84cdca..cb37fbd 100644
--- a/src/schema_compile_amend.c
+++ b/src/schema_compile_amend.c
@@ -135,8 +135,8 @@
 {
     uint32_t i;
     const struct lys_module *mod1, *mod2;
-    const char *name1, *name2;
-    size_t name1_len, name2_len;
+    const char *name1 = NULL, *name2 = NULL;
+    size_t name1_len = 0, name2_len = 0;
 
     if (exp1->used != exp2->used) {
         return 0;
@@ -1510,8 +1510,8 @@
 {
     uint32_t i;
     const struct lys_module *mod;
-    const char *name;
-    size_t name_len;
+    const char *name = NULL;
+    size_t name_len = 0;
 
     /* compare last node in the node ID */
     i = exp->used - 1;