[llvm-cov] Fix incorrect usage of .precision specifier in format() call.

Summary: Existing version doesn't work on Windows as it always prints 0.00.

Reviewers: Dor1s

Reviewed By: Dor1s

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42767

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323923 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed