drm/drv: Use // for comments in example code

This improves Sphinx output in two ways:

- It avoids an unmatched single-quote ('), about which Sphinx complained:

    Documentation/gpu/drm-internals.rst:298:
    WARNING: Could not lex literal_block as "c". Highlighting skipped.

  An alternative approach would be to replace "can't" with a word that
  doesn't have a single-quote.

- It lets Sphinx format the comments in italics and grey, making the
  code slightly easier to read.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: Daniel Vetter <daniel@ffwll.ch> [via irc]
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190808163629.14280-1-j.neuschaefer@gmx.net

drivers/gpu/drm/drm_drv.c

@@ -328,11 +328,9 @@ void drm_minor_release(struct drm_minor *minor)
  *		struct drm_device *drm;
  *		int ret;
  *
- *		[
- *		  devm_kzalloc() can't be used here because the drm_device
- *		  lifetime can exceed the device lifetime if driver unbind
- *		  happens when userspace still has open file descriptors.
- *		]
+ *		// devm_kzalloc() can't be used here because the drm_device '
+ *		// lifetime can exceed the device lifetime if driver unbind
+ *		// happens when userspace still has open file descriptors.
  *		priv = kzalloc(sizeof(*priv), GFP_KERNEL);
  *		if (!priv)
  *			return -ENOMEM;
@@ -355,7 +353,7 @@ void drm_minor_release(struct drm_minor *minor)
  *		if (IS_ERR(priv->pclk))
  *			return PTR_ERR(priv->pclk);
  *
- *		[ Further setup, display pipeline etc ]
+ *		// Further setup, display pipeline etc
  *
  *		platform_set_drvdata(pdev, drm);
  *
@@ -370,7 +368,7 @@ void drm_minor_release(struct drm_minor *minor)
  *		return 0;
  *	}
  *
- *	[ This function is called before the devm_ resources are released ]
+ *	// This function is called before the devm_ resources are released
  *	static int driver_remove(struct platform_device *pdev)
  *	{
  *		struct drm_device *drm = platform_get_drvdata(pdev);
@@ -381,7 +379,7 @@ void drm_minor_release(struct drm_minor *minor)
  *		return 0;
  *	}
  *
- *	[ This function is called on kernel restart and shutdown ]
+ *	// This function is called on kernel restart and shutdown
  *	static void driver_shutdown(struct platform_device *pdev)
  *	{
  *		drm_atomic_helper_shutdown(platform_get_drvdata(pdev));