internal/syscall/windows: convert CRLF line endings

CL 99337 introduced a file with CRLF line endings. Convert them to LF
line endings as in all other Go files.

Change-Id: I68b28fd443f05bebbbd9280d1821c4ccd33a4a8a
Reviewed-on: https://go-review.googlesource.com/108075
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>