i2c: take address space into account when checking for used addresses

It is not enough to compare the plain address value, we also need to
check the flags enabling a different address space. E.g. it is valid to
have address 0x50 as a 7-bit address and 0x050 as 10-bit address on the
same bus. Same for addresses when we are the slave.

Tested-by: Andrey Danin <[e-mail]>
Acked-by: Stephen Warren <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

drivers/i2c/i2c-core.c

···
 	struct i2c_client	*client = i2c_verify_client(dev);
 	int			addr = *(int *)addrp;
 
-	if (client && client->addr == addr)
+	if (client && i2c_encode_flags_to_addr(client) == addr)
 		return -EBUSY;
 	return 0;
 }
···
 	}
 
 	/* Check for address business */
-	status = i2c_check_addr_busy(adap, client->addr);
+	status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client));
 	if (status)
 		goto out_err;
 
···
 		return err;
 	}
 
-	/* Skip if already in use */
+	/* Skip if already in use (7 bit, no need to encode flags) */
 	if (i2c_check_addr_busy(adapter, addr))
 		return 0;
 
···
 			continue;
 		}
 
-		/* Check address availability */
+		/* Check address availability (7 bit, no need to encode flags) */
 		if (i2c_check_addr_busy(adap, addr_list[i])) {
 			dev_dbg(&adap->dev, "Address 0x%02x already in "
 				"use, not probing\n", addr_list[i]);