A @method annotation is only necessary when the docblock is not
directly followed by a function declaration (in which case JSDuck
assumes it documents a property), e.g. when defining an abstract
function or referencing a function from another library.
I verified that JSDuck generates exactly the same output before and
after this change (docs/data-<hash>.js files are identical).
Change-Id: I7edf51a8560ab9978b42800ab1026f0b5555c3bf
