remove unnecessary typecasting of realloc()

ares/ares_parse_ptr_reply.c

docs/examples/curlx.c

docs/examples/getinmemory.c

lib/base64.c

lib/http.c

lib/http_chunks.c

lib/http_digest.c

lib/mprintf.c

lib/transfer.c

lib/url.c

packages/OS400/ccsidcurl.c