Always deref filter context on flow-delete (#1093)

Signed-off-by: Alan Jowett <alan.jowett@microsoft.com>

Co-authored-by: Alan Jowett <alan.jowett@microsoft.com>

netebpfext/net_ebpf_ext_sock_ops.c

@@ -457,14 +457,14 @@ net_ebpf_extension_sock_ops_flow_delete(uint16_t layer_id, uint32_t callout_id,
     if (local_flow_context == NULL)
         goto Exit;
 
-    if (local_flow_context->client_detached)
-        // Since the hook client is detached, exit the function.
-        goto Exit;
-
     filter_context = local_flow_context->filter_context;
     if (filter_context == NULL)
         goto Exit;
 
+    if (local_flow_context->client_detached)
+        // Since the hook client is detached, exit the function.
+        goto Exit;
+
     attached_client = (net_ebpf_extension_hook_client_t*)filter_context->client_context;
     if (attached_client == NULL)
         // This means that the eBPF program is detached and there is nothing to notify.