QTextStreamPrivate::scan(): remove unnecessary checks

The delimiter search scan() loop detects a device or string reaching
the end of input and size limits. After that, 'false' is returned only
when no data was read at all. So, there is no a reason to test anything
except 'totalSize'.

Change-Id: Ib9cc21c0f4b7863c2dafb1bb074c5cda07387b8f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/io/qtextstream.cpp

@@ -681,15 +681,9 @@ bool QTextStreamPrivate::scan(const QChar **ptr, int *length, int maxlen, TokenD
              && (!maxlen || totalSize < maxlen)
              && (device && (canStillReadFromDevice = fillReadBuffer())));
 
-    // if the token was not found, but we reached the end of input,
-    // then we accept what we got. if we are not at the end of input,
-    // we return false.
-    if (!foundToken && (!maxlen || totalSize < maxlen)
-        && (totalSize == 0
-            || (string && stringOffset + totalSize < string->size())
-            || (device && !device->atEnd() && canStillReadFromDevice))) {
+    if (totalSize == 0) {
 #if defined (QTEXTSTREAM_DEBUG)
-        qDebug("QTextStreamPrivate::scan() did not find the token.");
+        qDebug("QTextStreamPrivate::scan() reached the end of input.");
 #endif
         return false;
     }