InputCommon: Use nested namespace specifiers where applicable

Source/Core/InputCommon/ControllerInterface/Quartz/Quartz.h

@@ -4,11 +4,8 @@
 
 #pragma once
 
-namespace ciface
-{
-namespace Quartz
+namespace ciface::Quartz
 {
 void PopulateDevices(void* window);
 void DeInit();
-}  // namespace Quartz
-}  // namespace ciface
+}  // namespace ciface::Quartz

Source/Core/InputCommon/ControllerInterface/Quartz/Quartz.mm

@@ -6,9 +6,7 @@
 #include "InputCommon/ControllerInterface/ControllerInterface.h"
 #include "InputCommon/ControllerInterface/Quartz/QuartzKeyboardAndMouse.h"
 
-namespace ciface
-{
-namespace Quartz
+namespace ciface::Quartz
 {
 void PopulateDevices(void* window)
 {
@@ -21,5 +19,4 @@ void PopulateDevices(void* window)
 void DeInit()
 {
 }
-}  // namespace Quartz
-}  // namespace ciface
+}  // namespace ciface::Quartz

Source/Core/InputCommon/ControllerInterface/Quartz/QuartzKeyboardAndMouse.h

@@ -8,9 +8,7 @@
 
 #include "InputCommon/ControllerInterface/Device.h"
 
-namespace ciface
-{
-namespace Quartz
+namespace ciface::Quartz
 {
 std::string KeycodeToName(const CGKeyCode keycode);
 
@@ -73,5 +71,4 @@ private:
 
   uint32_t m_windowid;
 };
-}  // namespace Quartz
-}  // namespace ciface
+}  // namespace ciface::Quartz

Source/Core/InputCommon/ControllerInterface/Quartz/QuartzKeyboardAndMouse.mm

@@ -9,9 +9,7 @@
 #include <Carbon/Carbon.h>
 #include <Cocoa/Cocoa.h>
 
-namespace ciface
-{
-namespace Quartz
+namespace ciface::Quartz
 {
 std::string KeycodeToName(const CGKeyCode keycode)
 {
@@ -223,5 +221,4 @@ std::string KeyboardAndMouse::Button::GetName() const
     return "Right Click";
   return std::string("Click ") + char('0' + m_button);
 }
-}  // namespace Quartz
-}  // namespace ciface
+}  // namespace ciface::Quartz