Fix various typos and spelling mistakes

Source/Core/DolphinQt/Settings/AudioPane.cpp

@@ -89,7 +89,7 @@ void AudioPane::CreateWidgets()
   const QFontMetrics font_metrics{font()};
   const int label_width = font_metrics.boundingRect(GetVolumeLabelText(100)).width();
   // Ensure the label is at least as wide as the QGroupBox title.
-  // This prevents [-Volume] title uglyness on Windows.
+  // This prevents [-Volume] title ugliness on Windows.
   const int title_width = font_metrics.boundingRect(volume_box->title()).width();
   m_volume_indicator->setFixedWidth(std::max(label_width, title_width));
 

Source/Core/DolphinQt/Settings/InterfacePane.cpp

@@ -131,7 +131,7 @@ void InterfacePane::CreateUI()
   m_combobox_language = MakeLanguageComboBox();
   combobox_layout->addRow(tr("&Language:"), m_combobox_language);
 
-  // List avalable themes
+  // List available themes
   auto theme_paths =
       Common::DoFileSearch({File::GetUserPath(D_THEMES_IDX), File::GetSysDirectory() + THEMES_DIR});
   std::vector<std::string> theme_names;