ipv4: eliminate lock count warnings in ping.c

Add lock release/acquire annotations to ping_seq_start() and
ping_seq_stop() to satisfy sparse.
Signed-off-by: NLance Richardson <lrichard@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/ping.c

@@ -1063,6 +1063,7 @@ static struct sock *ping_get_idx(struct seq_file *seq, loff_t pos)
 }
 
 void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family)
+	__acquires(ping_table.lock)
 {
 	struct ping_iter_state *state = seq->private;
 	state->bucket = 0;
@@ -1094,6 +1095,7 @@ void *ping_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 EXPORT_SYMBOL_GPL(ping_seq_next);
 
 void ping_seq_stop(struct seq_file *seq, void *v)
+	__releases(ping_table.lock)
 {
 	read_unlock_bh(&ping_table.lock);
 }