Addendum to 16d6c9b5e0
Giannis suggested and Thomas explained:
Before the Wine sync, comctl32/button.c was based on ROS's
user32/button.c, so _USER32_ would highlight changes between
user32 (originally based on Wine) and comctl32. Now our
comctl32/button.c is based on Wine's comctl32/button.c, so
__REACTOS__ is enough.
Fixes a regression that was introduced by Wine Staging 3.3 Sync.
Symptom was missing button text and icons for specific buttons
in Delphi applications, e.g. Double-Commander, Lazarus, Peazip.
The patch restores and ifdef-guards previous changes of Giannis.
