Print the coverage report location at the end of `acov-llvm.py report`.

This makes it easier to identify the directory where the coverage
report data of the latest `acov-llvm.py report` was written,
especially when the current directory already contains previous
coverage reports.

Test: acov-llvm.py report
Bug: 160401633
Change-Id: I96fc860940f5be11c4c3b702dfce74226afabfce
1 file changed