staging: comedi: vmk80xx: remove "firmware version" kernel messages

During the attach of this driver a couple commands are sent to the hardware
with usb_bulk_msg() to read the firmware version information. This information
is then dumped as dev_info() kernel messages. Thee messages are just added
noise and don't effect the operation of the driver.

For simplicity, remove the messages as well as the then unused functions
vmk80xx_read_eeprom() and vmk80xx_check_data_link().

This also fixes an issue reported by coverity about an out-of-bounds write
in vmk80xx_read_eeprom().

Reported-by: coverity (CID 711413)
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>