BPicture: Fix archive constructor.

The cleanup commit df48d3f9a8 broke
constructing a BPicture from an archive due to an incomplete rename.
The passed in BMessage was used as the data buffer instead of the
extracted data field.

Fixes the application side crash of #12340. Seeing how long this was
broken without anyone noticing, the feature doesn't seem to be very
popular.

src/kits/interface/Picture.cpp

@@ -184,7 +184,7 @@ BPicture::BPicture(BMessage* data)
 		// TODO: For now. We'll see if it's worth to support old style data
 		debugger("old style BPicture data is not supported");
 	} else if (version == 1) {
-		fExtent->ImportData(data, size);
+		fExtent->ImportData(pictureData, size);
 
 //		swap_data(fExtent->fNewData, fExtent->fNewSize);