sunvdc: Fix off-by-one in generic_request().

[ Upstream commit f4d96054 ]

The 'operations' bitmap corresponds one-for-one with the operation
codes, no adjustment is necessary.
Reported-by: Mark Kettenis <mark.kettenis@xs4all.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/block/sunvdc.c

@@ -461,7 +461,7 @@ static int generic_request(struct vdc_port *port, u8 op, void *buf, int len)
 	int op_len, err;
 	void *req_buf;
 
-	if (!(((u64)1 << ((u64)op - 1)) & port->operations))
+	if (!(((u64)1 << (u64)op) & port->operations))
 		return -EOPNOTSUPP;
 
 	switch (op) {