app/testpmd: add missing newline when showing statistics

app/testpmd: add missing newline when showing statistics

Having the standard stats and the rx burst stats on the same line gives a
really long line and is not consistent with the rest.

Before:
iofwd engine
  RX-packets: 121811360      TX-packets: 121811392      TX-dropped: 0               RX-bursts : 3806605 [100% of 32 pkts]
  TX-bursts : 3806606 [100% of 32 pkts]

csum engine
  RX-packets: 5467488        TX-packets: 5467520        TX-dropped: 0               RX- bad IP checksum: 0               Rx- bad L4 checksum: 0              Rx- bad outer L4 checksum: 0
  RX-bursts : 170859 [100% of 32 pkts]
  TX-bursts : 170860 [100% of 32 pkts]

After:
iofwd engine
  RX-packets: 259770560      TX-packets: 259770592      TX-dropped: 0
  RX-bursts : 8117830 [100% of 32 pkts]
  TX-bursts : 8117831 [100% of 32 pkts]

csum engine
  RX-packets: 7834016        TX-packets: 7834048        TX-dropped: 0               RX- bad IP checksum: 0               Rx- bad L4 checksum: 0              Rx- bad outer L4 checksum: 0
  RX-bursts : 244813 [100% of 32 pkts]
  TX-bursts : 244814 [100% of 32 pkts]

Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>