smack: Remove redundant assignments

Get rid of redundant assignments which end up in values not being
read either because they are overwritten or the function ends.

Reported by clang-tidy [deadcode.DeadStores]
Signed-off-by: Michal Orzel <michalorzel.eng@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

security/smack/smackfs.c

@@ -1192,7 +1192,6 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
 			rc = -EINVAL;
 			goto free_out;
 		}
-		m = BEBITS;
 		masks = 32;
 	}
 	if (masks > BEBITS) {