FIB: crash when deleting default route
FIB: crash when deleting default route

when adding a recursive path the table is locked
so that it can be removed when the last recursive path
is removed. however, not all RR source'd prefixs use
a recursive path. so flushing the table of all RR source'd
entries is not correct.

Change-Id: Id4010774011046e66ddc443ac83cb8e9245313dd
Signed-off-by: Neale Ranns <b9c0e9ef0223633bc2f318425f615cf5840a0be7@cisco.com>

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