[Sanitizer] Reland "Cleanup INTERCEPT_FUNCTION macro"

On Linux both version of the INTERCEPT_FUNCTION macro now return true
when interception was successful. Adapt and cleanup some usages.

Also note that `&(func) == &WRAP(func)` is a link-time property, but we
do a runtime check.

Tested on Linux and macOS.

Previous attempt reverted by: 5642c3fe

This attempt to bring order to the interceptor macro goes the other
direction and aligns the Linux implementation with the way things are
done on Windows.

Reviewed By: vitalybuka, rnk

Differential Revision: https://reviews.llvm.org/D61358

llvm-svn: 359725