remove unnecessary typecasting of calloc()

lib/cookie.c

lib/easy.c

lib/file.c

lib/formdata.c

lib/ftp.c

lib/hostip.c

lib/hostip4.c

lib/http.c

lib/multi.c

lib/ssh.c

lib/sslgen.c

lib/telnet.c

lib/url.c

packages/OS400/os400sys.c

src/urlglob.c