Merge branch 'kselftest-add-fixture-parameters'

Jakub Kicinski says:

====================
kselftest: add fixture parameters

This set is an attempt to make running tests for different
sets of data easier. The direct motivation is the tls
test which we'd like to run for TLS 1.2 and TLS 1.3,
but currently there is no easy way to invoke the same
tests with different parameters.

Tested all users of kselftest_harness.h.

Dave, would it be possible to take these via net-next?
It seems we're failing to get Shuah's attention.

v2:
 - don't run tests by fixture
 - don't pass params as an explicit argument

v3:
 - go back to the orginal implementation with an extra
   parameter, and running by fixture (Kees);
 - add LIST_APPEND helper (Kees);
 - add a dot between fixture and param name (Kees);
 - rename the params to variants (Tim);

v4:
 - whitespace fixes.

v5 (Kees):
 - move a comment;
 - remove a temporary variable;
 - reword the commit message on patch 4.

v6:
 - resend for net-next.

v1: https://lore.kernel.org/netdev/20200313031752.2332565-1-kuba@kernel.org/
v2: https://lore.kernel.org/netdev/20200314005501.2446494-1-kuba@kernel.org/
v3: https://lore.kernel.org/netdev/20200316225647.3129354-1-kuba@kernel.org/
v4: https://lore.kernel.org/netdev/20200317010419.3268916-1-kuba@kernel.org/
v5: https://lore.kernel.org/netdev/20200318010153.40797-1-kuba@kernel.org/
====================

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