util/cutils: Rename qemu_strtoll(), qemu_strtoull()

util/cutils: Rename qemu_strtoll(), qemu_strtoull()

The name qemu_strtoll() suggests conversion to long long, but it
actually converts to int64_t.  Rename to qemu_strtoi64().

The name qemu_strtoull() suggests conversion to unsigned long long,
but it actually converts to uint64_t.  Rename to qemu_strtou64().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <1487708048-2131-7-git-send-email-armbru@redhat.com>