rcu: Add sparse check for RCU_INIT_POINTER()

Add a sparse check when RCU_INIT_POINTER() is used to assign a non __rcu
annotated pointer.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

include/linux/rcupdate.h

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 295bb45..2c77561 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -1047,6 +1047,7 @@
  */
 #define RCU_INIT_POINTER(p, v) \
 	do { \
+		rcu_dereference_sparse(p, __rcu); \
 		p = RCU_INITIALIZER(v); \
 	} while (0)