rxrpc: rxkad: Casts are needed when comparing be32 values

Forced casts are needed to avoid sparse warning when directly comparing
be32 values.

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index ca746f3..3106a0c 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -142,7 +142,7 @@
 	crypto_blkcipher_encrypt_iv(&desc, &sg[0], &sg[1], sizeof(tmpbuf));
 
 	memcpy(&conn->csum_iv, &tmpbuf.x[2], sizeof(conn->csum_iv));
-	ASSERTCMP(conn->csum_iv.n[0], ==, tmpbuf.x[2]);
+	ASSERTCMP((u32 __force)conn->csum_iv.n[0], ==, (u32 __force)tmpbuf.x[2]);
 
 	_leave("");
 }