staging: comedi: addi_eeprom: cleanup v_EepromWaitBusy()

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

Rename the CamelCase local variable.

Refactor the do {} while to make the code 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>