strip newline for new comp perf .dat files

New comp perf .dat files were creaeted like:
#Date	perfKey

00/00/00	perfVal

this just removes the newline so there is no newline in a new .dat file
Merge pull request #653 from ronawho/fix-comp-perf-dat-files

strip newline for new compiler perf .dat files

[trivial, not reviewed]

New comp perf .dat files were created like:

#Date perfKey

00/00/00 perfVal

this just strips a newline so there is no newline after the header in a new .dat file:

#Date perfKey
00/00/00 perfVal