media: v4l: ctrl: Remove old documentation from v4l2_ctrl_grab

v4l2_ctrl_grab() is documented in the header; there's no need to have a
comment explaining what the function does in the .c file.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/v4l2-core/v4l2-ctrls.c

@@ -2511,12 +2511,6 @@ void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active)
 }
 EXPORT_SYMBOL(v4l2_ctrl_activate);
 
-/* Grab/ungrab a control.
-   Typically used when streaming starts and you want to grab controls,
-   preventing the user from changing them.
-
-   Just call this and the framework will block any attempts to change
-   these controls. */
 void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed)
 {
 	bool old;