[SPARC]: atomic_clear_mask build fix

This fixes one build error introduced in sparc with the patch of Oct 30,
resent Nov 4 "[patch 3/5] atomic: atomic_inc_not_zero" I still can't get
sparc to build, but at least it gets further after I remove this line. 
Apparently, this change was agreed to by Andrew and Nick on Nov 14, but
everyone thought someone else was doing it.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>