FIX: use valid local variable

tacaswell · efiring · commit 16cba9d4c39d · 2016-11-24T11:24:20.000-10:00
Due to `pcolorfast` returning an image or a collection, the proper
local variable is `ret`.
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -5825,8 +5825,8 @@ def pcolorfast(self, *args, **kwargs):
             ret.set_clim(vmin, vmax)
         else:
             ret.autoscale_None()
-        collection.stickies.x[:] = [xl, xr]
-        collection.stickies.y[:] = [yb, yt]
+        ret.stickies.x[:] = [xl, xr]
+        ret.stickies.y[:] = [yb, yt]
         self.update_datalim(np.array([[xl, yb], [xr, yt]]))
         self.autoscale_view(tight=True)
         return ret
