staging: r8188eu: remove ASSERT ifndef and macro definition

Remove ASSERT ifndef and macro definition from include/odm_debug.h, as
these are unused and therefore superfluous.

Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20210731003937.68615-6-phil@philpotter.co.uk


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>