Posix timers preallocate siqueue structures during timer creation
and keep them for reuse.  This allocation happens in user context
with no locks held, however it's designated as an atomic allocation.
Loosen this restriction, and while we're at it let's do a bit of code
consolidation so signal sending uses same __sigqueue_alloc() helper.
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>