net: em_canid: remove useless statements from em_canid_change
net: em_canid: remove useless statements from em_canid_change

tcf_ematch is allocated by kzalloc in function tcf_em_tree_validate(),
so cm_old is always NULL.

Signed-off-by: Duan Jiong <8328e395f8c1e2c56506478ccd778989e2637711@cn.fujitsu.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

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