* doc/lispref/frames.texi (Mouse Tracking): Fix typo.

doc/lispref/frames.texi

@@ -2256,7 +2256,7 @@ indicates the release of the button, or whatever kind of event means
 it is time to stop tracking.
 
 The @code{track-mouse} form causes Emacs to generate mouse motion
-events by binding the variable @code{mouse-tracking} to a
+events by binding the variable @code{track-mouse} to a
 non-@code{nil} value.  If that variable has the special value
 @code{dragging}, it additionally instructs the display engine to
 refrain from changing the shape of the mouse pointer.  This is