fbcon: don't draw cursor when it's disabled

When the cursor and echo are disabled on the current console, pressing a
key will cause a black rectangle to be painted in the cursor's position.
Fix this by not touching the framebuffer in fbcon_cursor() when the
cursor is off.
Signed-off-by: NMichal Januszewski <spock@gentoo.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/video/console/fbcon.c

@@ -1310,7 +1310,7 @@ static void fbcon_cursor(struct vc_data *vc, int mode)
 	int y;
  	int c = scr_readw((u16 *) vc->vc_pos);
 
-	if (fbcon_is_inactive(vc, info))
+	if (fbcon_is_inactive(vc, info) || vc->vc_deccm != 1)
 		return;
 
 	ops->cursor_flash = (mode == CM_ERASE) ? 0 : 1;