Make the code base clean under -Wwrite-strings.

I've also added that warning option and -Werror to the build script,
so that I'll find out if I break this property in future.

1 files changed, 1 insertions, 1 deletions

diff --git a/emcc.c b/emcc.c
index dbb4ab9..563fbe2 100644
--- a/emcc.c
+++ b/emcc.c
@@ -787,7 +787,7 @@ struct savefile_write_ctx {
     size_t pos;
 };
 
-static void savefile_write(void *vctx, void *buf, int len)
+static void savefile_write(void *vctx, const void *buf, int len)
 {
     struct savefile_write_ctx *ctx = (struct savefile_write_ctx *)vctx;
     if (ctx->buffer)