[Blackfin] arch: fix bug - breaking the atomic sections code.

The following cleanup patch:
  add __user markings to a few userspace system functions

mysteriously added a "&" operator that doesn't belong in there, breaking the
atomic sections code.

Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>