Doc: Fix snippet to match actual QFileInfo behavior

The documentation was already updated in abfac029ce,
but the snippet still incorrectly suggested QFileInfo::size would
report the actual size of an .lnk file on Windows.

Pick-to: 5.15 6.2 6.3
Change-Id: I03b96b2efcb713fbc4dd30fc526e1209806bf5cf
Reviewed-by: Oliver Wolff <oliver.wolff@qt.io>

src/corelib/doc/snippets/code/src_corelib_io_qfileinfo.cpp

@@ -77,7 +77,7 @@ info2.size();               // returns 56201
 QFileInfo info1("C:\\Users\\Bob\\untabify.lnk");
 info1.isSymLink();          // returns true
 info1.absoluteFilePath();   // returns "C:/Users/Bob/untabify.lnk"
-info1.size();               // returns 743
+info1.size();               // returns 63942
 info1.symLinkTarget();      // returns "C:/Pretty++/untabify"
 
 QFileInfo info2(info1.symLinkTarget());