Merge pull request libgit2#4087 from tiennou/warnings

Fix a few recent warnings

Author: Edward Thomson

include/git2/tree.h

@@ -381,7 +381,7 @@ GIT_EXTERN(int) git_treebuilder_write(
  *
  * @see git_treebuilder_write
  *
- * @param id Pointer to store the OID of the newly written tree
+ * @param oid Pointer to store the OID of the newly written tree
  * @param bld Tree builder to write
  * @param tree Shared buffer for writing the tree. Will be grown as necessary.
  * @return 0 or an error code

src/submodule.c

@@ -349,9 +349,10 @@ static int submodule_get_or_create(git_submodule **out, git_repository *repo, gi
 static int submodules_from_index(git_strmap *map, git_index *idx, git_config *cfg)
 {
 	int error;
-	git_iterator *i;
+	git_iterator *i = NULL;
 	const git_index_entry *entry;
 	git_strmap *names = 0;
+
 	git_strmap_alloc(&names);
 	if ((error = load_submodule_names(names, cfg)))
 		goto done;