Revert "cmake: check llvm-config in separate function"

This reverts commit 55c3efcb58cc153fc3109a61c6949e470b57b81e.

This caused a regression when building Zig with Homebrew.
Also I don't like that it prints a message on success. Only when there
is a problem should an error message be printed.

closes #14093
b1207b3293Andrew Kelley committed on 12/28/2022, 2:21:33 AMparent601ab9a
1 file changedLine totals unavailable