[llvm] [Instrumentation] Fix EdgeCounts vector size in SetBranchWeights (PR #99064)

[Mircea Trofin via llvm-commits]

mtrofin wrote:

> @mtrofin a week has passed, can we perhaps enlist a different reviewer?

Let's merge it at this point. Do you have commit rights?

https://github.com/llvm/llvm-project/pull/99064