drivers/net/hamradio: fix sparse warning: context imbalance

Impact: Attribute functions with __acquires(...) resp. __releases(...).

Fix this sparse warnings:
  drivers/net/hamradio/bpqether.c:387:13: warning: context imbalance in 'bpq_seq_start' - wrong count at exit
  drivers/net/hamradio/bpqether.c:419:13: warning: context imbalance in 'bpq_seq_stop' - unexpected unlock

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/hamradio/bpqether.c

@@ -386,6 +386,7 @@ static int bpq_close(struct net_device *dev)
  *	Proc filesystem
  */
 static void *bpq_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(RCU)
 {
 	int i = 1;
 	struct bpqdev *bpqdev;
@@ -418,6 +419,7 @@ static void *bpq_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 }
 
 static void bpq_seq_stop(struct seq_file *seq, void *v)
+	__releases(RCU)
 {
 	rcu_read_unlock();
 }