Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/net/wireless/wl1251/rx.c b/drivers/net/wireless/wl1251/rx.c
index c1b3b3f..6af3526 100644
--- a/drivers/net/wireless/wl1251/rx.c
+++ b/drivers/net/wireless/wl1251/rx.c
@@ -179,7 +179,7 @@
 	rx_buffer = skb_put(skb, length);
 	wl1251_mem_read(wl, rx_packet_ring_addr, rx_buffer, length);
 
-	/* The actual lenght doesn't include the target's alignment */
+	/* The actual length doesn't include the target's alignment */
 	skb->len = desc->length  - PLCP_HEADER_LENGTH;
 
 	fc = (u16 *)skb->data;