Fix some more memory leaks in error path

src/merge.c

@@ -1902,8 +1902,10 @@ static int write_merge_msg(
 	entries = git__calloc(heads_len, sizeof(struct merge_msg_entry));
 	GITERR_CHECK_ALLOC(entries); 
 
-	if (git_vector_init(&matching, heads_len, NULL) < 0)
+	if (git_vector_init(&matching, heads_len, NULL) < 0) {
+		git__free(entries);
 		return -1;
+	}
 
 	for (i = 0; i < heads_len; i++)
 		entries[i].merge_head = heads[i];

src/odb.c

@@ -232,6 +232,7 @@ int git_odb__hashlink(git_oid *out, const char *path)
 		link_data[size] = '\0';
 		if (read_len != (ssize_t)size) {
 			giterr_set(GITERR_OS, "Failed to read symlink data for '%s'", path);
+			git__free(link_data);
 			return -1;
 		}