platforms/drm: fix direct scanout check

(cherry picked from commit 49afd180)

src/plugins/platforms/drm/egl_gbm_backend.cpp

@@ -719,7 +719,7 @@ QSharedPointer<GLTexture> EglGbmBackend::textureForOutput(AbstractOutput *output
 
 bool EglGbmBackend::directScanoutAllowed(AbstractOutput *output) const
 {
-    return !m_backend->usesSoftwareCursor() && output->directScanoutInhibited();
+    return !m_backend->usesSoftwareCursor() && !output->directScanoutInhibited();
 }
 
 bool EglGbmBackend::hasOutput(AbstractOutput *output) const