vcs-svn: simplify cleanup in apply_one_window

Currently the cleanup code looks like this:

	free resources
	return 0;
 error_out:
	free resources
	return -1;

Avoid duplicating the "free resources" part by keeping the return
value in a variable and sharing code between the success and
exceptional case:

	ret = 0;
 out:
	free resources
	return ret;

Noticed in the svn-dump-fast-export project, where using the error()
macro in void context produces a warning.

Signed-off-by: David Barr <davidbarr@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

vcs-svn/svndiff.c

@@ -258,6 +258,7 @@ static int apply_window_in_core(struct window *ctx)
 static int apply_one_window(struct line_buffer *delta, off_t *delta_len,
 			    struct sliding_view *preimage, FILE *out)
 {
+	int rv = -1;
 	struct window ctx = WINDOW_INIT(preimage);
 	size_t out_len;
 	size_t instructions_len;
@@ -275,16 +276,15 @@ static int apply_one_window(struct line_buffer *delta, off_t *delta_len,
 	if (apply_window_in_core(&ctx))
 		goto error_out;
 	if (ctx.out.len != out_len) {
-		error("invalid delta: incorrect postimage length");
+		rv = error("invalid delta: incorrect postimage length");
 		goto error_out;
 	}
 	if (write_strbuf(&ctx.out, out))
 		goto error_out;
-	window_release(&ctx);
-	return 0;
+	rv = 0;
 error_out:
 	window_release(&ctx);
-	return -1;
+	return rv;
 }
 
 int svndiff0_apply(struct line_buffer *delta, off_t delta_len,