s390/cache: get rid of compile warning

Get rid of this one:

arch/s390/kernel/cache.c: In function 'cache_build_info':
arch/s390/kernel/cache.c:144: warning: 'private' may be used uninitialized
in this function
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/cache.c

@@ -146,15 +146,14 @@ static void __init cache_build_info(void)
 	ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
 	for (level = 0; level < CACHE_MAX_LEVEL; level++) {
 		switch (ct.ci[level].scope) {
-		case CACHE_SCOPE_NOTEXISTS:
-		case CACHE_SCOPE_RESERVED:
-			return;
 		case CACHE_SCOPE_SHARED:
 			private = 0;
 			break;
 		case CACHE_SCOPE_PRIVATE:
 			private = 1;
 			break;
+		default:
+			return;
 		}
 		if (ct.ci[level].type == CACHE_TYPE_SEPARATE) {
 			rc  = cache_add(level, private, CACHE_TYPE_DATA);