commit-tree: free commit message before exiting

This buffer is freed by the C runtime when commit-tree exits moments
later, but freeing it explicitly should make valgrind quieter.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/commit-tree.c

@@ -56,10 +56,12 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 	if (strbuf_read(&buffer, 0, 0) < 0)
 		die_errno("git commit-tree: failed to read");
 
-	if (!commit_tree(buffer.buf, tree_sha1, parents, commit_sha1, NULL)) {
-		printf("%s\n", sha1_to_hex(commit_sha1));
-		return 0;
-	}
-	else
+	if (commit_tree(buffer.buf, tree_sha1, parents, commit_sha1, NULL)) {
+		strbuf_release(&buffer);
 		return 1;
+	}
+
+	printf("%s\n", sha1_to_hex(commit_sha1));
+	strbuf_release(&buffer);
+	return 0;
 }