crypto: xor - Fix typo of optimization

s/optimzation/optimization/

Signed-off-by: Bhaskar Chowdhury <[e-mail]>
Acked-by: Randy Dunlap <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

crypto/xor.c

···
 	for (i = 0; i < 3; i++) {
 		start = ktime_get();
 		for (j = 0; j < REPS; j++) {
-			mb(); /* prevent loop optimzation */
+			mb(); /* prevent loop optimization */
 			tmpl->do_2(BENCH_SIZE, b1, b2);
 			mb();
 		}