eventfs: Use SRCU for freeing eventfs_inodes

To mirror the SRCU lock held in eventfs_iterate() when iterating over
eventfs inodes, use call_srcu() to free them too.

This was accidentally(?) degraded to RCU in commit 43aa6f9
("eventfs: Get rid of dentry pointers without refcounts").

Cc: Ajay Kaher <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/[email protected]
Fixes: 43aa6f9 ("eventfs: Get rid of dentry pointers without refcounts")
Signed-off-by: Mathias Krause <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

fs/tracefs/event_inode.c

@@ -112,7 +112,7 @@ static void release_ei(struct kref *ref)
 			entry->release(entry->name, ei->data);
 	}
 
-	call_rcu(&ei->rcu, free_ei_rcu);
+	call_srcu(&eventfs_srcu, &ei->rcu, free_ei_rcu);
 }
 
 static inline void put_ei(struct eventfs_inode *ei)