hwmon: (f75375s) Remove unnecessary and confusing initialization

f75375_probe calls i2c_get_clientdata to initialize the data pointer,
but there isn't yet any client data to get, and the value is never
used before the variable is assigned a new value seven lines later.

The call doesn't hurt anything and wastes only a couple of cycles.
The reason to fix it is because this module serves as an example to
hackers writing new hwmon drivers, and this part of the example is
confusing.

Signed-off-by: Andrew Klossner <andrew@cesa.opbu.xerox.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>