netfilter: ctnetlink: remove null test before kfree
netfilter: ctnetlink: remove null test before kfree

Fix checkpatch warning:
WARNING: kfree(NULL) is safe this check is probably not required

Signed-off-by: Fabian Frederick <3efd2a027b14fd890cd23a9ef6d1134b4e5ad850@skynet.be>
Signed-off-by: Pablo Neira Ayuso <707d14912bb250caf67dfe0ea4035681fbfc4f56@netfilter.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs