Support of windows drive letter in path to result dir.

Support of windows drive letter in path to result dir.

Parsing of path with IxNetwork test results has been fixed
to accept also windows drive letter. Change affects parsing
of TRAFFICGEN_IXNET_TESTER_RESULT_DIR configuration parameter.
Modified file:
* tools/pkt_gen/ixnet/ixnet.py

JIRA: VSPERF-27
Change-Id: I3dd6123e051952e6fd3f83cd9691341472d2960e
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Reviewed-by: Maryam Tahhan <maryam.tahhan@intel.com>
Reviewed-by: Billy O Mahony <billy.o.mahony@intel.com>
Reviewed-by: Dino Simeon Madarang <dino.simeonx.madarang@intel.com>
Reviewed-by: Radek Zetik <radekx.zetik@intel.com>
Reviewed-by: Eugene Snider <Eugene.Snider@huawei.com>
Reviewed-by: Gurpreet Singh <gurpreet.singh@spirent.com>
Reviewed-by: Tv Rao <tv.rao@freescale.com>