if number of bytes available for reading more than zero,set USRSOCK_EVENT_RECVFROM_AVAIL flag into the event Signed-off-by: wangchen <wangchen41@xiaomi.com>
if number of bytes available for reading more than zero,set USRSOCK_EVENT_RECVFROM_AVAIL flag into the event Signed-off-by: wangchen <wangchen41@xiaomi.com>