Revert "test: improve clean-up in test-fs-event"
Revert "test: improve clean-up in test-fs-event"

There were too many errors in this commits; it totally broke on
Windows. Besides, when the moon is dark, the cleanup code could delete
some random files from my hard drive.

This reverts commit 7573f4a4c4072fe90b448fe748bf27e53bee1c30.

urbit/archaeology2,urbit/archaeology2,urbit/archaeology2,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,urbit/archaeology2,unknownbrackets/maxcso,urbit/archaeology2,urbit/archaeology2,urbit/archaeology2,urbit/archaeology2,unknownbrackets/maxcso,urbit/archaeology2,unknownbrackets/maxcso,unknownbrackets/maxcso