[PATCH tip/core/rcu 14/20] rcu: Add comment headers to expedited-grace-period counter functions

These functions (rcu_exp_gp_seq_start(), rcu_exp_gp_seq_end(), rcu_exp_gp_seq_snap(), and rcu_exp_gp_seq_done() seemed too obvious to comment when written, but not so much when being documented. This commit therefore adds header comments to each of them. Signed-off-by: Paul E. McKenney

[PATCH tip/core/rcu 14/20] rcu: Add comment headers to expedited-grace-period counter functions

These functions (rcu_exp_gp_seq_start(), rcu_exp_gp_seq_end(), rcu_exp_gp_seq_snap(), and rcu_exp_gp_seq_done() seemed too obvious to comment when written, but not so much when being documented. This commit therefore adds header comments to each of them. Signed-off-by: Paul E. McKenney ---