compiler.h, kasan: Avoid duplicating __read_once_size_nocheck()

Instead of having two identical __read_once_size_nocheck() functions
with different attributes, consolidate all the difference in new macro
__no_kasan_or_inline and use it. No functional changes.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>