svm: fix byte accounting when allocating fifo header
svm: fix byte accounting when allocating fifo header

Type: fix

Change-Id: Ie50625271d257da814445ce13c2e6cd98986d523
Signed-off-by: Florin Coras <c9715e5cdf0718c2e9b10678757dfb027875eba2@cisco.com>

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