stats: fix vector overrun in expend check
stats: fix vector overrun in expend check

Do not access allocated elements beyond the end of the vector. They are
allocated, but not yet valid both logically (they are at best NULLs) and
according to ASAN.

Type: fix
Change-Id: Iaf43767d6d3bd4c24c7c5a0ba9b3410bbeeb0556
Signed-off-by: Dmitry Valter <997bc39781579eaf91cfcc2dbe19d04052bf53d3@yandex-team.ru>

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