kpty: declare KPtyPrivate and KPtyDevicePrivate as class rather than struct

because Q_DECLARE_PUBLIC() declares class clangs emmits warning that the
classes were previously declared as structs, this change is kinda of revert
of previous series of struct <-> class warnings fixes and may need changes
in other places (such as konsole from kde-baseapps) to fix the same issues
given that now the forementioned classes declaration has changed

Signed-off-by: Ivailo Monev <xakepa10@gmail.com>

kpty/kpty.h

@@ -23,7 +23,7 @@
 
 #include "kpty_export.h"
 
-struct KPtyPrivate;
+class KPtyPrivate;
 struct termios;
 
 /**

kpty/kpty_p.h

@@ -27,9 +27,10 @@
 
 #include <QtCore/QByteArray>
 
-struct KPtyPrivate {
+class KPtyPrivate {
     Q_DECLARE_PUBLIC(KPty)
 
+public:
     KPtyPrivate(KPty* parent);
     virtual ~KPtyPrivate();
 #ifndef HAVE_OPENPTY

kpty/kptydevice.cpp

@@ -245,9 +245,10 @@ static void qt_ignore_sigpipe()
 
 #define NO_INTR(ret,func) do { ret = func; } while (ret < 0 && errno == EINTR)
 
-struct KPtyDevicePrivate : public KPtyPrivate {
+class KPtyDevicePrivate : public KPtyPrivate {
     Q_DECLARE_PUBLIC(KPtyDevice)
 
+public:
     KPtyDevicePrivate(KPty* parent) :
         KPtyPrivate(parent),
         emittedReadyRead(false), emittedBytesWritten(false),

kpty/kptydevice.h

@@ -25,7 +25,7 @@
 
 #include <QtCore/QIODevice>
 
-struct KPtyDevicePrivate;
+class KPtyDevicePrivate;
 
 #define Q_DECLARE_PRIVATE_MI(Class, SuperClass) \
     inline Class##Private* d_func() { return reinterpret_cast<Class##Private *>(SuperClass::d_ptr); } \