Fix variable naming style in PPCBoolRetToInt.cpp (#144533)

Change loop variable 'i' to 'I' to conform to LLVM coding standards.
Variable names should start with an upper case letter according to LLVM
coding guidelines.
Fixed locations:
Lines 103-104: for loop variable and usage
Lines 257-258: for loop variable and usage

Co-authored-by: Shuqi Liang <Shuqi.Liang@ibm.com>
GitOrigin-RevId: e6f98ff4a81d6e6b66e164fe799cb5ef87b95682
1 file changed