Stats: prometheus export coverity errors.
Stats: prometheus export coverity errors.

Change-Id: Ibc0a25dcf7d734215e0cffe789b5726f23e1c3d7
Signed-off-by: Ole Troan <aeed71d78dc09e4764ceac69b111eee9b50cfdd0@cisco.com>

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