cppcheck: noExplicitConstructor

Change-Id: If888f3e0293565ea23158defbb6ac7553226a08f
Reviewed-on: https://gerrit.libreoffice.org/16147Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>

starmath/source/unofilter.cxx

@@ -30,7 +30,7 @@ class MathTypeFilter : public cppu::WeakImplHelper
     uno::Reference<lang::XComponent> m_xDstDoc;
 
 public:
-    MathTypeFilter(const uno::Reference<uno::XComponentContext>& xContext);
+    explicit MathTypeFilter(const uno::Reference<uno::XComponentContext>& xContext);
     virtual ~MathTypeFilter();
 
     // XFilter