vt: remove lines parameter from scrollback

It is always called with 0, so remove the parameter and pass the
default down to scrolldelta without checking.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h
index 8d76342..160f81f 100644
--- a/include/linux/vt_kern.h
+++ b/include/linux/vt_kern.h
@@ -45,7 +45,7 @@
 int con_font_op(struct vc_data *vc, struct console_font_op *op);
 int con_set_cmap(unsigned char __user *cmap);
 int con_get_cmap(unsigned char __user *cmap);
-void scrollback(struct vc_data *vc, int lines);
+void scrollback(struct vc_data *vc);
 void scrollfront(struct vc_data *vc, int lines);
 void clear_buffer_attributes(struct vc_data *vc);
 void update_region(struct vc_data *vc, unsigned long start, int count);