drivers/char: Convert remaining use of pr_warning to pr_warn

To enable eventual removal of pr_warning

This makes pr_warn use consistent for drivers/char

Prior to this patch, there were 1 use of pr_warning and
40 uses of pr_warn in drivers/char
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Amit Shah <amit@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/char/virtio_console.c

@@ -2302,7 +2302,7 @@ static int __init init(void)
 
 	pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL);
 	if (!pdrvdata.debugfs_dir)
-		pr_warning("Error creating debugfs dir for virtio-ports\n");
+		pr_warn("Error creating debugfs dir for virtio-ports\n");
 	INIT_LIST_HEAD(&pdrvdata.consoles);
 	INIT_LIST_HEAD(&pdrvdata.portdevs);