block_cache::Free() now accepts NULL pointers (it was already used this way before...).

Unmounting BFS volumes should now work as expected.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14034 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/cache/block_cache.cpp

@@ -215,6 +215,9 @@ block_cache::GetRange(void *address)
 void
 block_cache::Free(void *address)
 {
+	if (address == NULL)
+		return;
+
 	block_range *range = GetRange(address);
 	ASSERT(range != NULL);
 	range->Free(this, address);