Update parsers to use _updateTokenToNull() instead of _currToken = null

Author: cowtowncoder

cbor/src/main/java/com/fasterxml/jackson/dataformat/cbor/CBORParser.java

@@ -3804,7 +3804,7 @@ protected JsonToken _eofAsNextToken() throws IOException {
         // 30-Jan-2021, tatu: But also MUST verify that end-of-content is actually
         //   allowed (see [dataformats-binary#240] for example)
         _handleEOF();
-        return (_currToken = null);
+        return _updateTokenToNull();
     }
 
     /*

smile/src/main/java/com/fasterxml/jackson/dataformat/smile/SmileParser.java

@@ -487,7 +487,7 @@ public JsonToken nextToken() throws IOException
                         if (_currToken == null) {
                             return _nextAfterHeader();
                         }
-                        return (_currToken = null);
+                        return _updateTokenToNull();
                     }
                     _reportError("Unrecognized token byte 0x3A (malformed segment header?");
             	}
@@ -547,7 +547,7 @@ public JsonToken nextToken() throws IOException
                 _tokenIncomplete = true;
                 return (_currToken = JsonToken.VALUE_EMBEDDED_OBJECT);
             case 0x1F: // 0xFF, end of content
-                return (_currToken = null);
+                return _updateTokenToNull();
             }
             break;
         }
@@ -577,7 +577,7 @@ private JsonToken _nextAfterHeader() throws IOException
         if ((_inputPtr < _inputEnd) || _loadMore()) {
             if (_inputBuffer[_inputPtr] == SmileConstants.HEADER_BYTE_1) {
                 // danger zone; just set and return null token
-                return (_currToken = null);
+                return _updateTokenToNull();
             }
         }
         // Otherwise safe enough to do recursion
@@ -3117,7 +3117,7 @@ private final JsonToken _eofAsNextToken() throws IOException {
             _handleEOF();
         }
         close();
-        return (_currToken = null);
+        return _updateTokenToNull();
     }
 
     private void createChildArrayContext(final int lineNr, final int colNr) throws IOException {

smile/src/main/java/com/fasterxml/jackson/dataformat/smile/async/NonBlockingByteArrayParser.java

@@ -388,7 +388,7 @@ protected JsonToken _finishHeader(int state) throws IOException
                 _mayContainRawBinary = ((ch & SmileConstants.HEADER_BIT_HAS_RAW_BINARY) != 0);
             }
             _majorState = MAJOR_ROOT;
-            _currToken = null;
+            _updateTokenToNull();
 
             // Mild difference here: initial marker not reported separately, but in-line
             // ones need to be reported as `null` tokens as they are logical document end
@@ -503,7 +503,7 @@ private final JsonToken _startValue(int ch) throws IOException
                 // should we validate this is legal? (as per header)
                 return _startRawBinary();
             case 0x1F: // 0xFF, end of content
-                return (_currToken = null);
+                return _updateTokenToNull();
             }
             break;
         }

smile/src/main/java/com/fasterxml/jackson/dataformat/smile/async/NonBlockingParserBase.java

@@ -148,7 +148,7 @@ protected NonBlockingParserBase(IOContext ctxt, int parserFeatures, int smileFea
         // We don't need a lot; for most things maximum known a-priori length below 70 bytes
         _inputCopy = ctxt.allocReadIOBuffer(500);
 
-        _currToken = null;
+        _updateTokenToNull();
         _majorState = MAJOR_INITIAL;
     }
 
@@ -590,7 +590,7 @@ protected final JsonToken _eofAsNextToken() throws IOException {
             _handleEOF();
         }
         close();
-        return (_currToken = null);
+        return _updateTokenToNull();
     }
 
     protected final JsonToken _valueComplete(JsonToken t) throws IOException