service: Use nested namespace specifiers where applicable

There were a few places where nested namespace specifiers weren't being
used where they could be within the service code. This amends that to
make the namespacing a tiny bit more compact.

src/core/hle/service/mvd/mvd.cpp

@@ -5,12 +5,10 @@
 #include "core/hle/service/mvd/mvd.h"
 #include "core/hle/service/mvd/mvd_std.h"
 
-namespace Service {
-namespace MVD {
+namespace Service::MVD {
 
 void InstallInterfaces(SM::ServiceManager& service_manager) {
     std::make_shared<MVD_STD>()->InstallAsService(service_manager);
 }
 
-} // namespace MVD
-} // namespace Service
+} // namespace Service::MVD

src/core/hle/service/mvd/mvd.h

@@ -6,11 +6,9 @@
 
 #include "core/hle/service/service.h"
 
-namespace Service {
-namespace MVD {
+namespace Service::MVD {
 
 /// Initializes all MVD services.
 void InstallInterfaces(SM::ServiceManager& service_manager);
 
-} // namespace MVD
-} // namespace Service
+} // namespace Service::MVD

src/core/hle/service/mvd/mvd_std.cpp

@@ -5,8 +5,7 @@
 #include "core/hle/ipc_helpers.h"
 #include "core/hle/service/mvd/mvd_std.h"
 
-namespace Service {
-namespace MVD {
+namespace Service::MVD {
 
 MVD_STD::MVD_STD() : ServiceFramework("mvd:std", 1) {
     static const FunctionInfo functions[] = {
@@ -29,5 +28,4 @@ MVD_STD::MVD_STD() : ServiceFramework("mvd:std", 1) {
     RegisterHandlers(functions);
 };
 
-} // namespace MVD
-} // namespace Service
+} // namespace Service::MVD

src/core/hle/service/mvd/mvd_std.h

@@ -6,8 +6,7 @@
 
 #include "core/hle/service/service.h"
 
-namespace Service {
-namespace MVD {
+namespace Service::MVD {
 
 class MVD_STD final : public ServiceFramework<MVD_STD> {
 public:
@@ -15,5 +14,4 @@ public:
     ~MVD_STD() = default;
 };
 
-} // namespace MVD
-} // namespace Service
+} // namespace Service::MVD