Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
index 97c5b21..cdd6d04 100644
--- a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
+++ b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
@@ -71,7 +71,7 @@
 	if (reasm == NULL)
 		return NF_STOLEN;
 
-	/* error occured or not fragmented */
+	/* error occurred or not fragmented */
 	if (reasm == skb)
 		return NF_ACCEPT;