[PATCH] remove get_task_struct_rcu()

The latest set of signal-RCU patches does not use get_task_struct_rcu().
Attached is a patch that removes it.

Signed-off-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>