Bug 1856795 - Remove redundant member init r=emilio

Done with:
./mach static-analysis check --checks="-*, readability-redundant-member-init" --fix .

https://clang.llvm.org/extra/clang-tidy/checks/readability/redundant-member-init.html

Differential Revision: https://phabricator.services.mozilla.com/D190002

image/VectorImage.cpp

@@ -64,8 +64,7 @@ class SVGRootRenderingObserver final : public SVGRenderingObserver {
 
   SVGRootRenderingObserver(SVGDocumentWrapper* aDocWrapper,
                            VectorImage* aVectorImage)
-      : SVGRenderingObserver(),
-        mDocWrapper(aDocWrapper),
+      : mDocWrapper(aDocWrapper),
         mVectorImage(aVectorImage),
         mHonoringInvalidations(true) {
     MOZ_ASSERT(mDocWrapper, "Need a non-null SVG document wrapper");