misc: fix typos, doc, update copyright years

Updated FlowGetNew documentation, where it said NULL was only returned
in case of error.

src/app-layer.c

@@ -1,4 +1,4 @@
-/* Copyright (C) 2007-2021 Open Information Security Foundation
+/* Copyright (C) 2007-2023 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free

src/decode.h

@@ -1,4 +1,4 @@
-/* Copyright (C) 2007-2022 Open Information Security Foundation
+/* Copyright (C) 2007-2023 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free

src/defrag-hash.h

@@ -1,4 +1,4 @@
-/* Copyright (C) 2007-2012 Open Information Security Foundation
+/* Copyright (C) 2007-2023 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free

src/flow-hash.c

@@ -1,4 +1,4 @@
-/* Copyright (C) 2007-2022 Open Information Security Foundation
+/* Copyright (C) 2007-2023 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free
@@ -655,7 +655,8 @@ static inline void NoFlowHandleIPS(Packet *p)
  *  \param tv thread vars
  *  \param fls lookup support vars
  *
- *  \retval f *LOCKED* flow on success, NULL on error.
+ *  \retval f *LOCKED* flow on success, NULL on error or if we should not create
+ *  a new flow.
  */
 static Flow *FlowGetNew(ThreadVars *tv, FlowLookupStruct *fls, Packet *p)
 {

src/stream-tcp.h

@@ -95,7 +95,7 @@ typedef struct StreamTcpThread_ {
     uint16_t counter_tcp_midstream_pickups;
     /** wrong thread */
     uint16_t counter_tcp_wrong_thread;
-    /** ack for unseed data */
+    /** ack for unseen data */
     uint16_t counter_tcp_ack_unseen_data;
 
     /** tcp reassembly thread data */

src/util-exception-policy.c

@@ -1,4 +1,4 @@
-/* Copyright (C) 2022 Open Information Security Foundation
+/* Copyright (C) 2022-2023 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free

src/util-exception-policy.h

@@ -1,4 +1,4 @@
-/* Copyright (C) 2022 Open Information Security Foundation
+/* Copyright (C) 2022-2023 Open Information Security Foundation
  *
  * You can copy, redistribute or modify this Program under the terms of
  * the GNU General Public License version 2 as published by the Free