qlcnic: fix internal loopback test

o Loop 10 times with delay of 1 ms to rcv packet.
o Print garbage packet.
o Try send/receive MAX(16) packet, instead of exit from test,
  if a packet is not received.

Signed-off-by: Amit Kumar Salecha <amit.salecha@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>