drm/vmwgfx: Fix incorrect write to read-only register v2:

commit 4e578080 upstream.

Commit "drm/vmwgfx: correct fb_fix_screeninfo.line_length", while fixing a
vmwgfx fbdev bug, also writes the pitch to a supposedly read-only register:
SVGA_REG_BYTES_PER_LINE, while it should be (and also in fact is) written to
SVGA_REG_PITCHLOCK.

This patch is Cc'd stable because of the unknown effects writing to this
register might have, particularly on older device versions.

v2: Updated log message.

Cc: Christopher Friedt <chrisfriedt@gmail.com>
Tested-by: Christopher Friedt <chrisfriedt@gmail.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/gpu/drm/vmwgfx/vmwgfx_fb.c

@@ -179,7 +179,6 @@ static int vmw_fb_set_par(struct fb_info *info)
 		vmw_write(vmw_priv, SVGA_REG_DISPLAY_POSITION_Y, info->var.yoffset);
 		vmw_write(vmw_priv, SVGA_REG_DISPLAY_WIDTH, info->var.xres);
 		vmw_write(vmw_priv, SVGA_REG_DISPLAY_HEIGHT, info->var.yres);
-		vmw_write(vmw_priv, SVGA_REG_BYTES_PER_LINE, info->fix.line_length);
 		vmw_write(vmw_priv, SVGA_REG_DISPLAY_ID, SVGA_ID_INVALID);
 	}