gdksurface-win32.c: Rename window->surface as appropriate

Update the functions that were updated in the previous commit to have all
GdkSurface variables named as 'surface' instead of the GTK-3.x-era window, to
make things more consistent across the board.  Also fix formatting a bit.
13 jobs for fix-3728-3799 in 62 minutes and 26 seconds (queued for 4 seconds)
Status Name Job ID Coverage
  .Pre
failed style-check-diff #1648817
allowed to fail

00:08:29

 
  Build
passed fedora-x86_64 #1648818

00:20:05

passed installed-tests #1648820

00:18:50

passed macos #1648822
macos

00:13:29

passed msys2-mingw64 #1648821
win32-ps

00:08:03

passed release-build #1648819

00:19:01

passed vs2017-x64 #1648823
win32-ps

00:13:41

 
  Analysis
failed asan-build #1648825
asan allowed to fail

00:15:40

passed static-scan #1648824

00:30:58

 
  Docs
passed reference #1648826

00:18:54

 
  Flatpak
manual flatpak-manual:demo #1648827
flatpak allowed to fail manual
manual flatpak-manual:icon-browser #1648829
flatpak allowed to fail manual
manual flatpak-manual:widget-factory #1648828
flatpak allowed to fail manual
 
Name Stage Failure
failed
asan-build Analysis
 - a11y: 22 total, 22 pass, 0 fail
Processing gtk suite tools:
- tools: 4 total, 4 pass, 0 fail
Processing gtk suite reftest:
- reftest: 163 total, 160 pass, 3 fail
Processing gtk suite gtk+slow:
- gtk+slow: 1 total, 1 pass, 0 fail
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1

failed
style-check-diff .Pre
-				 GDK_TOPLEVEL_STATE_MAXIMIZED,
- 0);
+ GDK_TOPLEVEL_STATE_MAXIMIZED,
+ 0);

impl = GDK_WIN32_SURFACE (surface);

Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1