Silence warnings from using deprecated CUPS APIs

Apparently these APIs don't have any replacements that we
can use, so we have to continue to depend on them for now.
Silence the compiler warnings related to them, to avoid
unnecessary noise.

Change-Id: I1838e3c82bedd31529fdad8debc577dca17613e5
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/plugins/printsupport/cups/qppdprintdevice.cpp

@@ -52,6 +52,10 @@
 
 QT_BEGIN_NAMESPACE
 
+// avoid all the warnings about using deprecated API from CUPS (as there is no real replacement)
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_DEPRECATED
+
 QPpdPrintDevice::QPpdPrintDevice(const QString &id)
     : QPlatformPrintDevice(id),
       m_cupsDest(0),
@@ -508,4 +512,6 @@ cups_ptype_e QPpdPrintDevice::printerTypeFlags() const
     return static_cast<cups_ptype_e>(printerOption("printer-type").toUInt());
 }
 
+QT_WARNING_POP
+
 QT_END_NAMESPACE