[PATCH 1/4] block.c: fix compilation error on possible unitialized variable

[Cleber Rosa <crosa@redhat.com>]

GCC from CentOS Stream 8 is erroring out on a possibily unitialized
varible.

Full version info for the compiler used:

 gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-1)

Signed-off-by: Cleber Rosa <crosa@redhat.com>
---
 block.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block.c b/block.c
index 3f456892d0..08f29e6b65 100644
--- a/block.c
+++ b/block.c
@@ -4866,7 +4866,7 @@ static int bdrv_replace_node_common(BlockDriverState *from,
     Transaction *tran = tran_new();
     g_autoptr(GHashTable) found = NULL;
     g_autoptr(GSList) refresh_list = NULL;
-    BlockDriverState *to_cow_parent;
+    BlockDriverState *to_cow_parent = NULL;
     int ret;
 
     if (detach_subchain) {
-- 
2.25.4