avoid compiler warning when all storage backends are disabled

* src/storage_backend.c (backends): Add a NULL terminator.
(virStorageBackendForType): Use NULL terminator rather than
warning-provoking (possibly 0) array size.

ChangeLog

+Tue Oct 28 13:29:14 +0100 2008 Jim Meyering <meyering@redhat.com>
+
+	avoid compiler warning when all storage backends are disabled
+	* src/storage_backend.c (backends): Add a NULL terminator.
+	(virStorageBackendForType): Use NULL terminator rather than
+	warning-provoking (possibly 0) array size.
+
 Tue Oct 28 13:29:14 +0100 2008 Jim Meyering <meyering@redhat.com>
 
 	avoid many mingw-specific warnings

src/storage_backend.c

@@ -82,13 +82,14 @@ static virStorageBackendPtr backends[] = {
 #if WITH_STORAGE_DISK
     &virStorageBackendDisk,
 #endif
+    NULL
 };
 
 
 virStorageBackendPtr
 virStorageBackendForType(int type) {
     unsigned int i;
-    for (i = 0 ; i < ARRAY_CARDINALITY(backends); i++)
+    for (i = 0; backends[i]; i++)
         if (backends[i]->type == type)
             return backends[i];