Fixed common misspellings.

Mostly found by 'codespell'.

src/libhydra/kernel/kernel_listener.h

@@ -84,7 +84,7 @@ struct kernel_listener_t {
 					policy_dir_t direction, host_t *local, host_t *remote);
 
 	/**
-	 * Hook called if changes in the networking layer occured (interfaces
+	 * Hook called if changes in the networking layer occurred (interfaces
 	 * up/down, routes added/deleted etc.).
 	 *
 	 * @param address		TRUE if address list, FALSE if routing changed

src/libhydra/plugins/kernel_klips/kernel_klips_ipsec.c

@@ -2507,7 +2507,7 @@ static void init_ipsec_devices(private_kernel_klips_ipsec_t *this)
 }
 
 /**
- * Register a socket for AQUIRE/EXPIRE messages
+ * Register a socket for ACQUIRE/EXPIRE messages
  */
 static status_t register_pfkey_socket(private_kernel_klips_ipsec_t *this, u_int8_t satype)
 {

src/libhydra/plugins/kernel_pfkey/kernel_pfkey_ipsec.c

@@ -2327,7 +2327,7 @@ METHOD(kernel_ipsec_t, del_policy, status_t,
 }
 
 /**
- * Register a socket for AQUIRE/EXPIRE messages
+ * Register a socket for ACQUIRE/EXPIRE messages
  */
 static status_t register_pfkey_socket(private_kernel_pfkey_ipsec_t *this,
 									  u_int8_t satype)