net/pcap: fix infinite Rx with large files

net/pcap: fix infinite Rx with large files

Packet forwarding is not working when infinite Rx feature is used with
large .pcap files that has high number of packets.

The problem is number of allocated mbufs are less than the infinite Rx
ring size, and all mbufs consumed to fill the ring, so there is no mbuf
left for forwarding.

Current logic can not detect that infinite Rx ring is not filled
completely and no more mbufs left, and setup continues which leads
silent fail on packet forwarding.

There isn't much can be done when there is not enough mbuf for the given
.pcap file, so additional checks added to detect the case and fail
explicitly with an error log.

Bugzilla ID: 595
Fixes: a3f5252e5cbd ("net/pcap: enable infinitely Rx a pcap file")
Cc: stable@dpdk.org
Reported-by: Cian Ferriter <cian.ferriter@intel.com>
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Cian Ferriter <cian.ferriter@intel.com>