remove eof whitespace lines

remove eof whitespace lines

Summary:
Remove lint errors from folly: trailing newlines

find folly | xargs arc lint | grep -B3 EOF | grep ">>>" | egrep -o "folly[^:]*" | xargs -n1 sed -i '$d'

folly/experimental/io/test/AsyncIOTest.cpp had two trailing newlines,
the second was removed by hand

@override-unit-failures

Test Plan:
fbconfig -r folly && fbmake runtests

Pretty overkill for a whitespace diff, but why not.

Reviewed By: robbert@fb.com

Subscribers: sdwilsh, fugalh, njormrod

FB internal diff: D1561213