Merge branch 'getsockopt-parameter-validation'

Gavrilov Ilia says:

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fix incorrect parameter validation in the *_get_sockopt() functions

This v2 series fix incorrent parameter validation in *_get_sockopt()
functions in several places.

version 2 changes:
- reword the patch description
- add two patches for net/kcm and net/x25
====================

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