selftests: kselftest_harness.h: fix kernel-doc markups

The kernel-doc markups there is violating the expected
syntax, causing it to not parse the name of the
markup identifier properly, preventing it to check
if the kernel-doc matches the #define below each
markup.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/697640045663f1366beb15e76e78b420dac5f5a2.1603791716.git.mchehab+huawei@kernel.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>