fs: ext4: Use CRC-16 implementation from linux/crc16.h

Implementation in linux/crc16.h provides standard CRC-16 algorithm with
polynomial x^16 + x^15 + x^2 + 1. Use it and remove duplicate ext4 CRC-16
specific code.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>
5 files changed