drm/vmwgfx: Potential off by one in vmw_view_add()

drm/vmwgfx: Potential off by one in vmw_view_add()

commit 0d9cac0ca0429830c40fe1a4e50e60f6221fd7b6 upstream.

The vmw_view_cmd_to_type() function returns vmw_view_max (3) on error.
It's one element beyond the end of the vmw_view_cotables[] table.

My read on this is that it's possible to hit this failure.  header->id
comes from vmw_cmd_check() and it's a user controlled number between
1040 and 1225 so we can hit that error.  But I don't have the hardware
to test this code.

Fixes: d80efd5cb3de ("drm/vmwgfx: Initial DX support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>