llvm/tools/sancov/sancov.cpp: 3 * Function parameter should be passed by const reference

[dcb314]

Static analyser cppcheck says:

trunk/llvm/tools/sancov/sancov.cpp:1054:60: performance: Function parameter 'FileNames' should be passed by const reference. [passedByValue]
trunk/llvm/tools/sancov/sancov.cpp:450:41: performance: Function parameter 'Path' should be passed by const reference. [passedByValue]
trunk/llvm/tools/sancov/sancov.cpp:870:54: performance: Function parameter 'ObjectFile' should be passed by const reference. [passedByValue]