FakeVim: Focus current editor before handling command line command

Action like "Switch Header/Source" need to be performed in correct
context, in this case "CppEditor.C++Editor". But while command line is
focused the context is global.

Change-Id: Id9aa24641508a08f5196d314edc74644780c26d9
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/fakevim/fakevimhandler.cpp

@@ -4376,6 +4376,7 @@ EventResult FakeVimHandler::Private::handleExMode(const Input &input)
         // FIXME: Complete actual commands.
         g.commandBuffer.historyUp();
     } else if (input.isReturn()) {
+        editor()->focus();
         showMessage(MessageCommand, g.commandBuffer.display());
         handleExCommand(g.commandBuffer.contents());
         g.commandBuffer.clear();