Kernel symbols aren't correctly handled in the guest linker

[dstolfa]

When trying to use backtick (`) in a script to get a kernel symbol, we don't correctly figure out the initial type in the guest:

dt_infer_type(uload, 3): failed to get class
dtrace: failed to infer a type for 3

This is caused by us trying to infer the type on the host kernel first, rather than the guest kernel, and it ends up with a type mismatch.