spelling: s/trough/through/

Additionally, one comment was reformulated by Joe Perches <joe@perches.com>.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c
index 95bd07b..315be47 100644
--- a/drivers/parisc/led.c
+++ b/drivers/parisc/led.c
@@ -347,7 +347,7 @@
    ** 
    ** led_get_net_activity()
    ** 
-   ** calculate if there was TX- or RX-troughput on the network interfaces
+   ** calculate if there was TX- or RX-throughput on the network interfaces
    ** (analog to dev_get_info() from net/core/dev.c)
    **   
  */