Doc: silence some warnings from QDirListing

The type doesn't have hasNext/next member functions, and
the fileInfo/fileName/filePath functions are members of the
nested DirEntry type.

Since the DirEntry type is not documented, linking to it will
still fail. Adding documentation for that type is an exercise
for a future commit.

Amends c39a0d1e89.

Change-Id: Ib223905123264271ce090a991cd73936b49edaae
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>
(cherry picked from commit 71053abba3b9a6aed51793e7259c34e431b714f9)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/corelib/io/qdirlisting.cpp

@@ -396,7 +396,7 @@ bool QDirListingPrivate::hasIterators() const
     \note To list symlinks that point to non existing files, QDir::System
     must be set in \a dir's QDir::Filters.
 
-    \sa hasNext(), next(), IteratorFlags
+    \sa IteratorFlags
 */
 QDirListing::QDirListing(const QDir &dir, IteratorFlags flags)
     : d(new QDirListingPrivate)
@@ -421,7 +421,7 @@ QDirListing::QDirListing(const QDir &dir, IteratorFlags flags)
     \note To list symlinks that point to non existing files, QDir::System
     must be set in \a filters.
 
-    \sa hasNext(), next(), IteratorFlags
+    \sa IteratorFlags
 */
 QDirListing::QDirListing(const QString &path, QDir::Filters filters, IteratorFlags flags)
     : d(new QDirListingPrivate)
@@ -439,7 +439,7 @@ QDirListing::QDirListing(const QString &path, QDir::Filters filters, IteratorFla
     By default, \a flags is NoIteratorFlags, which provides the same behavior
     as in QDir::entryList().
 
-    \sa hasNext(), next(), IteratorFlags
+    \sa IteratorFlags
 */
 QDirListing::QDirListing(const QString &path, IteratorFlags flags)
     : d(new QDirListingPrivate)
@@ -466,7 +466,7 @@ QDirListing::QDirListing(const QString &path, IteratorFlags flags)
     \note To list symlinks that point to non existing files, QDir::System
     must be set in \a flags.
 
-    \sa hasNext(), next(), IteratorFlags, QDir::setNameFilters()
+    \sa IteratorFlags, QDir::setNameFilters()
 */
 QDirListing::QDirListing(const QString &path, const QStringList &nameFilters, QDir::Filters filters,
                          IteratorFlags flags)
@@ -524,7 +524,7 @@ QString QDirListing::iteratorPath() const
     Here's how to find and read all files filtered by name, recursively:
     \snippet code/src_corelib_io_qdirlisting.cpp 1
 
-    \sa fileInfo(), fileName(), filePath()
+    \sa QDirListing::DirEntry
 */
 QDirListing::const_iterator QDirListing::begin() const
 {