KASAN can't change FRAME_WARN

[Shi, Yang]

Hi Andrey,

When I enable KASAN for 4.5 and 4.6 (I didn't try with older versions), 
I got FRAME_WARN warning for frame size exceeds 2048 bytes.

Then I found the kconfig looks like:

range 0 8192
default 0 if KASAN
default 1024 if !64BIT
default 2048 if 64BIT

In my understanding, FRAME_WARN should be 0 once KASAN is enabled, but 
it is still 2048. I tried a couple of fixes, i.e.

default 0 if KASAN
default 1024 if (!KASAN && !64BIT)
default 2048 if (!KASAN && 64BIT)

But, nothing works, so I have to add "depends on !KASAN" to disable 
FRAME_WARN completely, but it causes the kernel image size increased.

Any hint is appreciated.

Thanks,
Yang