rcu: Move RCU CPU stall-warning code out of tree.c

This commit completes the process of consolidating the code for RCU CPU
stall warnings for normal grace periods by moving the remaining such
code from kernel/rcu/tree.c to kernel/rcu/tree_stall.h.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
3 files changed