RemoteLinux: Use the "install to local dir" step in derived plugins

That is, Boot2Qt and Qnx.

Task-number: QTCREATORBUG-22822
Change-Id: Id48069c6ee2bc857a94be173b6c1de9bc69404a8
Reviewed-by: hjk <hjk@qt.io>

src/plugins/remotelinux/makeinstallstep.cpp

@@ -45,7 +45,6 @@ using namespace ProjectExplorer;
 using namespace Utils;
 
 namespace RemoteLinux {
-namespace Internal {
 
 const char MakeAspectId[] = "RemoteLinux.MakeInstall.Make";
 const char InstallRootAspectId[] = "RemoteLinux.MakeInstall.InstallRoot";
@@ -228,5 +227,4 @@ bool MakeInstallStep::fromMap(const QVariantMap &map)
     return true;
 }
 
-} // namespace Internal
 } // namespace RemoteLinux