Use isSVG*Element() helpers more in SVG code (Part 4)

Source/core/svg/SVGLinearGradientElement.cpp

Index: Source/core/svg/SVGLinearGradientElement.cpp
diff --git a/Source/core/svg/SVGLinearGradientElement.cpp b/Source/core/svg/SVGLinearGradientElement.cpp
index abb5db0a1bcf3e162d16ea5dfe3976ae57694dc1..37b5c65be2ae9a11f7ef3c55abed2b73c463e0f3 100644
--- a/Source/core/svg/SVGLinearGradientElement.cpp
+++ b/Source/core/svg/SVGLinearGradientElement.cpp
@@ -170,7 +170,7 @@ bool SVGLinearGradientElement::collectGradientAttributes(LinearGradientAttribute
             if (!current->renderer())
                 return false;
 
-            setGradientAttributes(current, attributes, current->hasTagName(SVGNames::linearGradientTag));
+            setGradientAttributes(current, attributes, isSVGLinearGradientElement(*current));
             processedGradients.add(current);
         } else {
             return true;