ui-blob: fix resource leak: free before return

Coverity-id: 13944
Signed-off-by: Christian Hesse <mail@eworm.de>
diff --git a/ui-blob.c b/ui-blob.c
index 70a671e..1ded839 100644
--- a/ui-blob.c
+++ b/ui-blob.c
@@ -171,4 +171,5 @@
 	ctx.page.filename = path;
 	cgit_print_http_headers();
 	html_raw(buf, size);
+	free(buf);
 }