sched: Add USER_SCHED to feature removal list

Peter Zijlstra suggested that we remove USER_SCHED at:

   http://lkml.org/lkml/2009/3/21/67

Removing USER_SCHED removes a lot of code from the scheduler
and simplifies the code.

We already have the ability to do user based classification
which is tightened using PAM in userspace.

Schedule USER_SCHED for removal in 2.6.34

Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Bharata B Rao <bharata@linux.vnet.ibm.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
LKML-Reference: <20091103214544.GI5495@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>