staging: comedi: addi_eeprom: cleanup v_EepromCs76Read()

Add namespace to the function by renaming the CamelCase function to
addi_eeprom_read_93c76().

Change the return type of the function to unsigned short and just
return the read value instead of passing it through a pointer.

Rename the CamelCase parameters and local variables.

Make addi_eeprom_cmd_93c76() return the last value so it does not
need to be calculated.

Rename the EE_READ and EE76_CMD_LEN defines so they have namespace
associated with the other 93c76 defines.

Cleanup the loop that reads the eeprom bits so it's a bit more concise.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>