tap: replaces strlen to vec_len
tap: replaces strlen to vec_len

Type: fix

Change-Id: I478b6fc54c47f0e77a1470ed29fdd56774671441
Signed-off-by: Mohsin Kazmi <3be96aed1fe21f963e790909e1d3a8e57ce776f2@cisco.com>

chrisy/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp