PM / devfreq: remove redundant null pointer check before kfree

kfree has taken the null pointer into account. hence it is safe
to remove the redundant null pointer check before kfree.

Signed-off-by: zhong jiang <[e-mail]>
Signed-off-by: MyungJoo Ham <[e-mail]>

drivers/devfreq/devfreq.c

···
 	devfreq_remove_device(devfreq);
 	devfreq = NULL;
 err_dev:
-	if (devfreq)
-		kfree(devfreq);
+	kfree(devfreq);
 err_out:
 	return ERR_PTR(err);
 }