Commit 100504d2 introduced using GetDpiForWindow().
Unfortunately NOTEPAD_LoadSettingFromRegistry is executed when
the main window is not yet created, resulting in
having Globals.lfFont.lfHeight=0.
This is later stored in the registry in iPointSize=0.

In a fresh wine prefix there are not yet registry values created,
therefore the first run of notepad does not show this problem,
and iPointSize is saved with a sane value to the registry.

Having Globals.lfFont.lfHeight=0 manifests for example
in cups PDF prints being a single empty page.

The check of point_size for having a non-zero value should also fix
wine prefixes which have already a stored registry value of iPointSize=0.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55852