[PATCH] ttm_get_pages() will OOPS with highmem allocation

[Jonathan Morton]

Reposting from this kernel bug:
https://bugzilla.kernel.org/show_bug.cgi?id=50241

I've tested the patch and it solves a highly repeatable OOPS with the
CedarView driver that I'm porting.

Reviewed-by: Thomas Hellstrom <thellstrom at vmware.com>