Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/include/net/sock.h b/include/net/sock.h
index da0534d..01810a3 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1749,7 +1749,7 @@
 
 /*
  * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
- * They should not hold a referrence to a namespace in order to allow
+ * They should not hold a reference to a namespace in order to allow
  * to stop it.
  * Sockets after sk_change_net should be released using sk_release_kernel
  */