gui: Use SetSizerAndFit after dialogs are constructed.

It seems to fix the button UI problem for Linux wx3.0 builds.

pcsx2/gui/Dialogs/ConfirmationDialogs.cpp

@@ -147,6 +147,7 @@ wxWindowID pxIssueConfirmation( wxDialogWithHelpers& confirmDlg, const MsgButton
 
 	confirmDlg += new ModalButtonPanel( &confirmDlg, buttons ) | pxCenter.Border( wxTOP, 8 );
 	buttons.SetBestFocus( confirmDlg );
+	confirmDlg.SetSizerAndFit(confirmDlg.GetSizer());
 	return confirmDlg.ShowModal();
 }
 

pcsx2/gui/Dialogs/GameDatabaseDialog.cpp

@@ -26,4 +26,6 @@ Dialogs::GameDatabaseDialog::GameDatabaseDialog(wxWindow* parent)
 	ScopedBusyCursor busy( Cursor_ReallyBusy );
 	*this += new GameDatabasePanel(this) | StdExpand();
 	AddOkCancel();
+
+	SetSizerAndFit(GetSizer());
 }

pcsx2/gui/Dialogs/LogOptionsDialog.cpp

@@ -28,4 +28,6 @@ Dialogs::LogOptionsDialog::LogOptionsDialog( wxWindow* parent )
 {
 	*this += new LogOptionsPanel( this ) | StdExpand();
 	AddOkCancel();
+
+	SetSizerAndFit(GetSizer());
 }

pcsx2/gui/Dialogs/SysConfigDialog.cpp

@@ -229,6 +229,8 @@ Dialogs::SysConfigDialog::SysConfigDialog(wxWindow* parent)
 	AddOkCancel();
 	AddPresetsControl();
 
+	SetSizerAndFit(GetSizer());
+
 	if( wxGetApp().Overrides.HasCustomHacks() )
 		wxGetApp().PostMethod( CheckHacksOverrides );
 }
@@ -248,11 +250,13 @@ Dialogs::ComponentsConfigDialog::ComponentsConfigDialog(wxWindow* parent)
 	AddListbook();
 	AddOkCancel();
 
+	SetSizerAndFit(GetSizer());
+
 	if( wxGetApp().Overrides.HasPluginsOverride() )
 		wxGetApp().PostMethod( CheckPluginsOverrides );
 }
 
-
+// FIXME: Purge? It's unused and does nothing.
 Dialogs::InterfaceConfigDialog::InterfaceConfigDialog(wxWindow *parent)
 	: BaseConfigurationDialog( parent, AddAppName(_("Appearance/Themes - %s")), 400 )
 {
@@ -281,6 +285,8 @@ Dialogs::InterfaceLanguageDialog::InterfaceLanguageDialog(wxWindow* parent)
 	*this += new Panels::LanguageSelectionPanel(this, false) | StdCenter();
 
 	AddOkCancel();
+
+	SetSizerAndFit(GetSizer());
 }
 
 // ------------------------------------------------------------------------