Fix afs_lookup_volume_rcu() so that it doesn't leak a dying volume if
afs_try_get_volume() fails.

Fixes: 32222f09782f ("afs: Apply server breaks to mmap'd files in the call processor")
Closes: https://sashiko.dev/#/patchset/20260609081738.770127-1-dhowells%40redhat.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Deepakkumar Karn <dkarn@redhat.com>
cc: linux-afs@lists.infradead.org
---
 fs/afs/callback.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index 74853e0d0435..61354003c006 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -134,6 +134,7 @@ static struct afs_volume *afs_lookup_volume_rcu(struct afs_cell *cell,
 
 		if (volume && afs_try_get_volume(volume, afs_volume_trace_get_callback))
 			break;
+		volume = NULL;
 	}
 
 	return volume;