vlib: fix memory leak on process nodes reforking
vlib: fix memory leak on process nodes reforking

The processes vector leaked on reforking and needs to be
freed before recloning from main node processes.

Type: fix
Signed-off-by: Vladislav Grishenko <f00e66fbbe96bb8dd2df4e1fa4eb52430c5b92c3@yandex-team.ru>
Change-Id: Id69bc3fd42e2efacfcd521f98e6e51a9c712fef5

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