[Static Analyzer] No longer include the full path of the source file in the...

[Static Analyzer] No longer include the full path of the source file in the single file tests' bug identifiers.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241292 91177308-0d34-0410-b5e6-96231b3b80d8