[llvm][NFC] Refactor code to use ProfDataUtils

[llvm][NFC] Refactor code to use ProfDataUtils

In this patch we replace common code patterns with the use of utility
functions for dealing with profiling metadata. There should be no change
in functionality, as the existing checks should be preserved in all
cases.

Reviewed By: bogner, davidxl

Differential Revision: https://reviews.llvm.org/D128860