rxrpc: Fix the min security level for kernel calls

Fix the kernel call initiation to set the minimum security level for kernel
initiated calls (such as from kAFS) from the sockopt value.

Fixes: 19ffa01c ("rxrpc: Use structs to hold connection params and protocol info")
Signed-off-by: NDavid Howells <dhowells@redhat.com>

net/rxrpc/af_rxrpc.c

@@ -313,7 +313,7 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
 	memset(&cp, 0, sizeof(cp));
 	cp.local		= rx->local;
 	cp.key			= key;
-	cp.security_level	= 0;
+	cp.security_level	= rx->min_sec_level;
 	cp.exclusive		= false;
 	cp.upgrade		= upgrade;
 	cp.service_id		= srx->srx_service;