Get rid of getStride()

It was confusing and not properly used everywhere.
Callers should use the stride they get when they get
the buffer pointer.
diff --git a/vncviewer/PlatformPixelBuffer.cxx b/vncviewer/PlatformPixelBuffer.cxx
index 8a24690..ced0446 100644
--- a/vncviewer/PlatformPixelBuffer.cxx
+++ b/vncviewer/PlatformPixelBuffer.cxx
@@ -20,7 +20,7 @@
 
 PlatformPixelBuffer::PlatformPixelBuffer(const rfb::PixelFormat& pf,
                                          int width, int height,
-                                         rdr::U8* data) :
-  FullFramePixelBuffer(pf, width, height, data)
+                                         rdr::U8* data, int stride) :
+  FullFramePixelBuffer(pf, width, height, data, stride)
 {
 }