dpdkstat: Fix metrics' types

dpdkstat: Fix metrics' types

This patch fixes parsing of metrics' types. Some statistics, such as
rx_q0errors, rx_q0bytes or rx_q0packet, don't contain suffix _errors, _bytes or
_packets. This has caused them to use generic type 'derive', rather than
more specific one, for instance 'if_rx_errors'. Additionally, some
statistics contain string 'error', rather than 'errors'.

Change-Id: Ifd4ed6c0d2c21723900f36fb1a376d4673e59850
Signed-off-by: Przemyslaw Szczerbik <przemyslawx.szczerbik@intel.com>