win: remove unused variable in test/test-fs.c
win: remove unused variable in test/test-fs.c

PR-URL: https://github.com/libuv/libuv/pull/1632
Reviewed-By: Colin Ihrig <838f779c91673db29b8572ea3f54d191d3878ae2@gmail.com>
Reviewed-By: Refael Ackermann <0604a90ccdde7a0adfa2ff3857349859a7209740@gmail.com>
Reviewed-By: Santiago Gimeno <3f17e29e343c4cf8809fb0970d81d6d8ee88d6b3@gmail.com>

unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso