firewire: ohci: prevent aliasing of locally handled register addresses

We must compute the offset from the CSR register base with the
full 48 address bits to prevent matching with addresses whose
lower 32 bits happen to be equal with one of the specially
handled registers.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/ohci.c

@@ -1198,8 +1198,7 @@ static void handle_local_lock(struct fw_ohci *ohci,
 
 static void handle_local_request(struct context *ctx, struct fw_packet *packet)
 {
-	u64 offset;
-	u32 csr;
+	u64 offset, csr;
 
 	if (ctx == &ctx->ohci->at_request_ctx) {
 		packet->ack = ACK_PENDING;