[generator] Use the correct javadoc element (#934)

Fixes: #933
Fixes a bug when attempting to find the `<javadoc/>` element that is
associated with a specific member name and jni-signature. When a type
contained multiple members with the same name, we would always return
the first `<javadoc/>` that matched the member name, rather than the
one that matched both the name and signature.

Author: pjcollins

tools/generator/Java.Interop.Tools.Generator.Transformation/JavadocFixups.cs

@@ -100,7 +100,7 @@ static XElement GetMemberJavadoc (XElement typeJavadoc, string elementName, stri
 returntypeJavadoc
 .Elements(elementName)
 .Where(e =>jniSignature==(string)e.Attribute("jni-signature")&&
-name==null?true:name==(string)e.Attribute("name"))
+(name==null?true:name==(string)e.Attribute("name")))
 .Elements("javadoc")
 .FirstOrDefault();
 }