uzlib_uncompress_init: Don't set source_limit and readSource fields.

This function is supposed to initialize just the internal state of the
decompressor. Any "public API" fields should be set by user (and all of
source, source_limit and source_read_cb need to be set explicitly by
user in the latest version).

src/tinflate.c

@@ -494,8 +494,6 @@ void uzlib_init(void)
 void uzlib_uncompress_init(TINF_DATA *d, void *dict, unsigned int dictLen)
 {
    d->eof = 0;
-   d->source_limit = NULL;
-   d->readSource = NULL;
    d->bitcount = 0;
    d->bfinal = 0;
    d->btype = -1;