Cycles: Correction to image extension setting commit

Technically it was all wrong and it should have been called Extend instead
of Clip. Got confused by the naming in different libraries.

More options are still to come.

intern/cycles/render/nodes.cpp

@@ -1375,7 +1375,7 @@ PointDensityTextureNode::~PointDensityTextureNode()
 		image_manager->remove_image(filename,
 		                            builtin_data,
 		                            interpolation,
-		                            EXTENSION_CLIP);
+		                            EXTENSION_REPEAT);
 	}
 }
 
@@ -1419,7 +1419,7 @@ void PointDensityTextureNode::compile(SVMCompiler& compiler)
 			                                false, 0,
 			                                is_float, is_linear,
 			                                interpolation,
-			                                EXTENSION_CLIP,
+			                                EXTENSION_REPEAT,
 			                                true);
 		}
 
@@ -1467,7 +1467,7 @@ void PointDensityTextureNode::compile(OSLCompiler& compiler)
 			                                false, 0,
 			                                is_float, is_linear,
 			                                interpolation,
-			                                EXTENSION_CLIP,
+			                                EXTENSION_REPEAT,
 			                                true);
 		}