selftests: arm64: Fix -Waddress warning in tpidr2 test

selftests: arm64: Fix -Waddress warning in tpidr2 test

Thanks to -Waddress, the compiler warns that the ksft_test_result()
invocations in the arm64 tpidr2 selftest are always true. Oops.

Fix the test by, err, actually running the test functions.

Fixes: 6d80cb73131d ("kselftest/arm64: Convert tpidr2 test to use kselftest.h")
Signed-off-by: Bala-Vignesh-Reddy <reddybalavignesh9979@gmail.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>