Fix docs for renderBufferImmediate

Looking at the code I saw that it actually does not take a Material as
input. I suppose it's a leftover from an old implementation.

Signed-off-by: martinRenou <[email protected]>

docs/api/en/renderers/WebGLRenderer.html

@@ -427,12 +427,11 @@
 		<h3>[method:null renderBufferDirect]( [param:Camera camera], [param:Fog fog], [param:Geometry geometry], [param:Material material], [param:Object3D object], [param:Object group] )</h3>
 		<p>Render a buffer geometry group using the camera and with the specified material.</p>
 
-		<h3>[method:null renderBufferImmediate]( [param:Object3D object], [param:shaderprogram program], [param:Material shading] )</h3>
+		<h3>[method:null renderBufferImmediate]( [param:Object3D object], [param:shaderprogram program] )</h3>
 		<p>object - an instance of [page:Object3D]<br />
 		program - an instance of shaderProgram<br />
-		shading - an instance of Material<br /><br />
 
-		Render an immediate buffer. Gets called by renderImmediateObject.
+		Render an immediate buffer. Gets called by renderObjectImmediate.
 		</p>
 
 		<h3>[method:null setAnimationLoop]( [param:Function callback] )</h3>