vcs: invoke the vt update callback when /dev/vcs* is written to

A notifier chain is called whenever the vt code modifies a terminal
content, except for one case which is when the modification comes
through writes to /dev/vcs* devices.  Let's add the missing notifier
invocation at the end of vcs_write() for that case too.
Signed-off-by: Nicolas Pitre <nicolas.pitre@canonical.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/char/vc_screen.c

@@ -538,6 +538,8 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
 	}
 	*ppos += written;
 	ret = written;
+	if (written)
+		vcs_scr_updated(vc);
 
 unlock_out:
 	release_console_sem();

drivers/char/vt.c

@@ -4182,6 +4182,11 @@ void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org)
 	}
 }
 
+void vcs_scr_updated(struct vc_data *vc)
+{
+	notify_update(vc);
+}
+
 /*
  *	Visible symbols for modules
  */

include/linux/selection.h

@@ -39,5 +39,6 @@ extern void putconsxy(struct vc_data *vc, unsigned char *p);
 
 extern u16 vcs_scr_readw(struct vc_data *vc, const u16 *org);
 extern void vcs_scr_writew(struct vc_data *vc, u16 val, u16 *org);
+extern void vcs_scr_updated(struct vc_data *vc);
 
 #endif