[tests] Do no free objects that are allocated on the stack

gcc4.4 warns about these kind of objects. Fix that.
diff --git a/tests/sms/sms_test.c b/tests/sms/sms_test.c
index 2b55b97..dfc43cf 100644
--- a/tests/sms/sms_test.c
+++ b/tests/sms/sms_test.c
@@ -90,10 +90,6 @@
 		printf("Wanted: '%s' got '%s'\n", input, result);
 	}
 
-	free(coded);
-	free(result);
-
-
 	for(i=0;i<SMS_NUM;i++) {
 		/* Setup SMS msgb */
 		msg = msgb_alloc(sms_data[i].len);