misc: microchip: pci1xxxx: Fix return value of nvmem callbacks

misc: microchip: pci1xxxx: Fix return value of nvmem callbacks

Read/write callbacks registered with nvmem core expect 0 to be returned
on success and a negative value to be returned on failure.

Currently pci1xxxx_otp_read()/pci1xxxx_otp_write() and
pci1xxxx_eeprom_read()/pci1xxxx_eeprom_write() return the number of
bytes read/written on success.
Fix to return 0 on success.

Fixes: 9ab5465349c0 ("misc: microchip: pci1xxxx: Add support to read and write into PCI1XXXX EEPROM via NVMEM sysfs")
Fixes: 0969001569e4 ("misc: microchip: pci1xxxx: Add support to read and write into PCI1XXXX OTP via NVMEM sysfs")
Cc: stable@vger.kernel.org
Signed-off-by: Joy Chakraborty <joychakr@google.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240612070031.1215558-1-joychakr@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>