hw/usb/core.c: reorder usage and assertion of p->ep Reorder the code so the assertion of p->ep occurs before it is used in the subsequent lines. Signed-off-by: Sergei Heifetz <heifetz@yandex-team.com> Reviewed-by: Laurent Vivier <laurent@vivier.eu> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>