Merge branch 'rmnet-checksums-part-2'

Alex Elder says:

====================
net: qualcomm: rmnet: MAPv4 download checksum cleanup, part 2

This is part 2 of a large series that reworks some code that handles
downloaded packets when MAPv4 checksum offload is enabled.  The
first part, which includes an overview, is here:
  https://lore.kernel.org/netdev/20210611190529.3085813-1-elder@linaro.org/

This second part of the series completes the simplification of this
handling code, removing unnecessary byte swaps and bitwise inversions
of checksum values, and along the way avoids the need for almost all
of the forced type casts.  The checksum field in an RMNet download
trailer is given __sum16_t type to accurately reflect the meaning of
that field.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>