qemu-sockets: Fix buffer overflow in inet_parse()

The size of the stack allocated host[] array didn't account for the
terminating '\0' byte that sscanf() writes. Fix the array size.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
