The NIU device refuses to allow accesses to MSI-X registers before MSI-X
is enabled.  This patch fixes the problem by moving the read of the mask
register to after MSI-X is enabled.
Reported-by: NDavid S. Miller <davem@davemloft.net>
Tested-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>