i7core_edac: fix panic in udimm sysfs attributes registration

i7core_edac: fix panic in udimm sysfs attributes registration

Array of udimm sysfs attributes was not ended with NULL marker, leading to
dereference of random memory.

  EDAC DEBUG: edac_create_mci_instance_attributes: edac_create_mci_instance_attributes() file udimm0
  EDAC DEBUG: edac_create_mci_instance_attributes: edac_create_mci_instance_attributes() file udimm1
  EDAC DEBUG: edac_create_mci_instance_attributes: edac_create_mci_instance_attributes() file udimm2
  BUG: unable to handle kernel NULL pointer dereference at 00000000000001a4
  IP: [<ffffffff81330b36>] edac_create_mci_instance_attributes+0x148/0x1f1
  Pid: 1, comm: swapper Not tainted 2.6.36-rc3-nv+ #483 P6T SE/System Product Name
  RIP: 0010:[<ffffffff81330b36>]  [<ffffffff81330b36>] edac_create_mci_instance_attributes+0x148/0x1f1
  (...)
  Call Trace:
   [<ffffffff81330b86>] edac_create_mci_instance_attributes+0x198/0x1f1
   [<ffffffff81330c9a>] edac_create_sysfs_mci_device+0xbb/0x2b2
   [<ffffffff8132f533>] edac_mc_add_mc+0x46b/0x557
   [<ffffffff81428901>] i7core_probe+0xccf/0xec0
  RIP  [<ffffffff81330b36>] edac_create_mci_instance_attributes+0x148/0x1f1
  ---[ end trace 20de320855b81d78 ]---
  Kernel panic - not syncing: Attempted to kill init!

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Doug Thompson <dougthompson@xmission.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>