wanrouter: fix sparse warnings: context imbalance

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

Fix this sparse warnings:
  net/wanrouter/wanproc.c:82:13: warning: context imbalance in 'r_start' - wrong count at exit
  net/wanrouter/wanproc.c:103:13: warning: context imbalance in 'r_stop' - unexpected unlock
  net/wanrouter/wanmain.c:765:13: warning: context imbalance in 'lock_adapter_irq' - wrong count at exit
  net/wanrouter/wanmain.c:771:13: warning: context imbalance in 'unlock_adapter_irq' - unexpected unlock

Signed-off-by: Hannes Eder <hannes@hanneseder.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/wanrouter/wanproc.c b/net/wanrouter/wanproc.c
index 267f7ff..c44d96b 100644
--- a/net/wanrouter/wanproc.c
+++ b/net/wanrouter/wanproc.c
@@ -80,6 +80,7 @@
  *	Iterator
  */
 static void *r_start(struct seq_file *m, loff_t *pos)
+	__acquires(kernel_lock)
 {
 	struct wan_device *wandev;
 	loff_t l = *pos;
@@ -101,6 +102,7 @@
 }
 
 static void r_stop(struct seq_file *m, void *v)
+	__releases(kernel_lock)
 {
 	unlock_kernel();
 }