meson: fix incorrect egl_drm operator in build

Back when the meson build was still in the PR state, this particular
variable was a dictionary. Later, it was refactored to simply be a
feature object instead. All uses of egl_drm['use'] should have been
replaced with egl_drm.allowed() but this particular line was missed
(that's what I get for not just doing find/replace). The conditional in
this line is usually satisified before egl_drm ever needs to be checked
which was why no one noticed until now. Fixes #9631.

meson.build

@@ -1427,7 +1427,7 @@ vaapi = {
     'deps': dependency('libva', version: '>= 1.1.0', required: get_option('vaapi')),
 }
 vaapi += {'use': vaapi['deps'].found() and libdl.found() and
-          (x11['use'] or wayland['use'] or egl_drm['use'])}
+          (x11['use'] or wayland['use'] or egl_drm.allowed())}
 if vaapi['use']
     dependencies += vaapi['deps']
     features += vaapi['name']