linux-cp: fix coverity 216937
linux-cp: fix coverity 216937

Initialize the host_sw_if_index to ~0 so in the error cases
the variable is set to something predictable.

Type: fix
Change-Id: Ic55e4f0cbfa286e85dfb54b89b5321af18a439a1
Signed-off-by: Andrew Yourtchenko <eb6233fe2fbd585844f4fb8426b53b186ab379b1@gmail.com>

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