net/802: fix sparse warnings: context imbalance

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

Fix this sparse warnings:
  net/802/tr.c:492:21: warning: context imbalance in 'rif_seq_start' - wrong count at exit
  net/802/tr.c:519:13: warning: context imbalance in 'rif_seq_stop' - unexpected unlock

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

net/802/tr.c

@@ -486,6 +486,7 @@ static struct rif_cache *rif_get_idx(loff_t pos)
 }
 
 static void *rif_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(&rif_lock)
 {
 	spin_lock_irq(&rif_lock);
 
@@ -517,6 +518,7 @@ static void *rif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 }
 
 static void rif_seq_stop(struct seq_file *seq, void *v)
+	__releases(&rif_lock)
 {
 	spin_unlock_irq(&rif_lock);
 }