NetCP: Deletion of unnecessary checks before two function calls

The functions cpsw_ale_destroy() and of_dev_put() test whether their argument
is NULL and then return immediately. Thus the test around the call
is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: David S. Miller <davem@davemloft.net>