A build condition was missing around a compilation test, this compilation
test comes from the original test_bitfield code.

And removed unnecessary code for this test.

Fixes: d2585f51 ("lib: kunit: add bitfield test conversion to KUnit")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Vitor Massaru Iha <vitor@massaru.org>
Link: https://lore.kernel.org/linux-next/20201015163056.56fcc835@canb.auug.org.au/


Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

This adds the conversion of the runtime tests of test_bitfield,
from `lib/test_bitfield.c` to KUnit tests.

Code Style Documentation: [0]

Signed-off-by: Vitor Massaru Iha <vitor@massaru.org>
Link: [0] https://lore.kernel.org/linux-kselftest/20200620054944.167330-1-davidgow@google.com/T/#u


Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Add tests for the bitfield helpers. The constant ones will all
be folded to nothing by the compiler (if everything is correct
in the header file), and the variable ones do some tests against
open-coding the necessary shifts.

A few test cases that should fail/warn compilation are provided
under ifdef.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>