Fix compiler perf testing.
Fix compiler perf testing.

Update sha1 dat file code to use $datdir instead of $perfdir when computing the
dat file path. This looks like it was a simple typo, as $datdir is computed a
handful of lines above.

pr: da39a3ee5e6b4b0d3255bfef95601890afd80709@ronawho

hildeth/chapel,CoryMcCartan/chapel,chizarlicious/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,hildeth/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,chizarlicious/chapel,hildeth/chapel,chizarlicious/chapel,chizarlicious/chapel,CoryMcCartan/chapel,chizarlicious/chapel,hildeth/chapel,hildeth/chapel,hildeth/chapel,chizarlicious/chapel,hildeth/chapel,CoryMcCartan/chapel,chizarlicious/chapel