hwmon: (pmbus/max8688) Accept negative page register values

[ Upstream commit a46f8cd ]

A negative page register value means that no page needs to be
selected. This is used by status register evaluations and needs
to be accepted.

Fixes: da8e48a ("hwmon: (pmbus) Always call _pmbus_read_byte in core driver")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwmon/pmbus/max8688.c

@@ -44,7 +44,7 @@ static int max8688_read_word_data(struct i2c_client *client, int page, int reg)
 {
  int ret;
 
- if (page)
+ if (page > 0)
  return -ENXIO;
 
  switch (reg) {