VCL: Fix Coverity CID183003
VCL: Fix Coverity CID183003

*** CID 183003:  Program hangs  (LOCK)
/src/vcl/vppcom.c: 2988 in vppcom_session_accept()

Change-Id: I123b73198d305fb0226516942caa410d3647a6bc
Signed-off-by: Dave Wallace <0ed937c0e4b2f09f7bc24acf16cee52b8a199d5f@gmail.com>

FDio/vpp,FDio/vpp,vpp-dev/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,vpp-dev/vpp,FDio/vpp,vpp-dev/vpp,FDio/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,vpp-dev/vpp,chrisy/vpp,vpp-dev/vpp,vpp-dev/vpp,chrisy/vpp,chrisy/vpp,chrisy/vpp,vpp-dev/vpp,chrisy/vpp,FDio/vpp