QmlJS: Simplify code, fix MSVC-warning.
QmlJS: Simplify code, fix MSVC-warning.

qmljsviewercontext.cpp:80: warning: C4715:
'QmlJS::ViewerContext::languageIsCompatible':
: not all control paths return a value.

Change-Id: I22279ef7a43873b9c8f3d73d3826b59d5abaa390
Reviewed-by: Fawzi Mohamed <7388270c57edd0fabd71d8eb0322d66e3c40e57e@digia.com>

AltarBeastiful/qt-creator,danimo/qt-creator,xianian/qt-creator,darksylinc/qt-creator,Distrotech/qtcreator,martyone/sailfish-qtcreator,darksylinc/qt-creator,kuba1/qtcreator,colede/qtcreator,danimo/qt-creator,AltarBeastiful/qt-creator,maui-packages/qt-creator,colede/qtcreator,farseerri/git_code,farseerri/git_code,amyvmiwei/qt-creator,AltarBeastiful/qt-creator,kuba1/qtcreator,AltarBeastiful/qt-creator,AltarBeastiful/qt-creator,Distrotech/qtcreator,omniacreator/qtcreator,maui-packages/qt-creator,danimo/qt-creator,darksylinc/qt-creator,amyvmiwei/qt-creator,danimo/qt-creator,omniacreator/qtcreator,omniacreator/qtcreator,danimo/qt-creator,xianian/qt-creator,Distrotech/qtcreator,colede/qtcreator,kuba1/qtcreator,omniacreator/qtcreator,darksylinc/qt-creator,martyone/sailfish-qtcreator,danimo/qt-creator,Distrotech/qtcreator,xianian/qt-creator,maui-packages/qt-creator,martyone/sailfish-qtcreator,darksylinc/qt-creator,kuba1/qtcreator,martyone/sailfish-qtcreator,amyvmiwei/qt-creator,omniacreator/qtcreator,kuba1/qtcreator,martyone/sailfish-qtcreator,darksylinc/qt-creator,danimo/qt-creator,amyvmiwei/qt-creator,danimo/qt-creator,xianian/qt-creator,kuba1/qtcreator,omniacreator/qtcreator,AltarBeastiful/qt-creator,xianian/qt-creator,maui-packages/qt-creator,maui-packages/qt-creator,colede/qtcreator,maui-packages/qt-creator,danimo/qt-creator,Distrotech/qtcreator,Distrotech/qtcreator,darksylinc/qt-creator,kuba1/qtcreator,farseerri/git_code,colede/qtcreator,xianian/qt-creator,Distrotech/qtcreator,omniacreator/qtcreator,colede/qtcreator,colede/qtcreator,kuba1/qtcreator,farseerri/git_code,amyvmiwei/qt-creator,amyvmiwei/qt-creator,farseerri/git_code,kuba1/qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,maui-packages/qt-creator,farseerri/git_code,martyone/sailfish-qtcreator,xianian/qt-creator,farseerri/git_code,xianian/qt-creator,amyvmiwei/qt-creator,darksylinc/qt-creator,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,farseerri/git_code,amyvmiwei/qt-creator,martyone/sailfish-qtcreator