rcu: Remove for_each_rcu_flavor() flavor-traversal macro

Now that there is only ever a single flavor of RCU in a given kernel
build, there isn't a whole lot of point in having a flavor-traversal
macro.  This commit therefore removes it and converts calls to it to
straightline code, inlining trivial functions as appropriate.

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

kernel/rcu/tree.h

@@ -360,7 +360,6 @@ struct rcu_state {
 						/*  jiffies. */
 	const char *name;			/* Name of structure. */
 	char abbr;				/* Abbreviated name. */
-	struct list_head flavors;		/* List of RCU flavors. */
 
 	spinlock_t ofl_lock ____cacheline_internodealigned_in_smp;
 						/* Synchronize offline with */
@@ -417,12 +416,6 @@ static const char *tp_rcu_varname __used __tracepoint_string = rcu_name;
 #define RCU_NAME rcu_name
 #endif /* #else #ifdef CONFIG_TRACING */
 
-extern struct list_head rcu_struct_flavors;
-
-/* Sequence through rcu_state structures for each RCU flavor. */
-#define for_each_rcu_flavor(rsp) \
-	list_for_each_entry((rsp), &rcu_struct_flavors, flavors)
-
 /*
  * RCU implementation internal declarations:
  */