[PATCH] srcu: Export srcu_check_nmi_safety() to modules

[Zqiang]

When enable CONFIG_PROVE_RCU and built modules, the following
error appear:

ERROR: modpost: "srcu_check_nmi_safety" [kernel/rcu/rcutorture.ko] undefined!
ERROR: modpost: "srcu_check_nmi_safety" [kernel/rcu/rcuscale.ko] undefined!

This commit fix it by exporting the srcu_check_nmi_safety().

Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx>
---
 kernel/rcu/srcutree.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index 382236dd5e46..bcd629f5f902 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -651,6 +651,7 @@ void srcu_check_nmi_safety(struct srcu_struct *ssp, bool nmi_safe)
 	}
 	WARN_ONCE(old_nmi_safe_mask != nmi_safe_mask, "CPU %d old state %d new state %d\n", sdp->cpu, old_nmi_safe_mask, nmi_safe_mask);
 }
+EXPORT_SYMBOL_GPL(srcu_check_nmi_safety);
 #endif /* CONFIG_PROVE_RCU */
 
 /*
-- 
2.25.1