MIPS: Loongson: Fix phys_mem_access_prot() check

The check used to determine if uncached accelerated should be used or not
is wrong. The parenthesis are misplaced and making the test fail.

Signed-off-by: Arnaud Patard <apatard@mandriva.com>
To: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1161/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>