hw/block/nvme: fix namespaces array to 1-based

subsys->namespaces array used to be sized to NVME_SUBSYS_MAX_NAMESPACES.
But subsys->namespaces are being accessed with 1-based namespace id
which means the very first array entry will always be empty(NULL).

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Tested-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>

hw/block/nvme-subsys.h

@@ -24,7 +24,7 @@ typedef struct NvmeSubsystem {
 
     NvmeCtrl    *ctrls[NVME_SUBSYS_MAX_CTRLS];
     /* Allocated namespaces for this subsystem */
-    NvmeNamespace *namespaces[NVME_SUBSYS_MAX_NAMESPACES];
+    NvmeNamespace *namespaces[NVME_SUBSYS_MAX_NAMESPACES + 1];
 
     struct {
         char *nqn;