net/dsa/dsa.c: remove unnecessary null test before kfree
net/dsa/dsa.c: remove unnecessary null test before kfree

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

Cc: "David S. Miller" <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>
Cc: Grant Likely <9069e6f5a2b566e2674a0ba1e2bf39c12c195fad@linaro.org>
Cc: 1099b3bee480025a15c1b622ecdea77a1d6d7166@vger.kernel.org
Cc: Joe Perches <16a9a54ddf4259952e3c118c763138e83693d7fd@perches.com>
Signed-off-by: Fabian Frederick <3efd2a027b14fd890cd23a9ef6d1134b4e5ad850@skynet.be>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

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