remove unnecessary typecasting of malloc()

ares/ares_init.c

ares/ares_parse_ptr_reply.c

docs/examples/curlx.c

docs/examples/fopen.c

docs/examples/opensslthreadlock.c

lib/base64.c

lib/content_encoding.c

lib/cookie.c

lib/easy.c

lib/formdata.c

lib/ftp.c

lib/hash.c

lib/http.c

lib/http_chunks.c

lib/http_digest.c

lib/llist.c

lib/mprintf.c

lib/multi.c

lib/nss.c

lib/nwlib.c