Remove deprecated Wuffs io_buffer::reader calls

Bug: skia:8235
Change-Id: I5a73089c8c9febd3cedf41d0f2e3a52baebda1c9
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/227956
Commit-Queue: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
diff --git a/src/codec/SkWuffsCodec.cpp b/src/codec/SkWuffsCodec.cpp
index b4c840b..4480b79 100644
--- a/src/codec/SkWuffsCodec.cpp
+++ b/src/codec/SkWuffsCodec.cpp
@@ -728,7 +728,7 @@
 
 const char* SkWuffsCodec::decodeFrameConfig() {
     while (true) {
-        const char* status = fDecoder->decode_frame_config(&fFrameConfig, fIOBuffer.reader());
+        const char* status = fDecoder->decode_frame_config(&fFrameConfig, &fIOBuffer);
         if ((status == wuffs_base__suspension__short_read) &&
             fill_buffer(&fIOBuffer, fStream.get())) {
             continue;
@@ -742,7 +742,7 @@
 const char* SkWuffsCodec::decodeFrame() {
     while (true) {
         const char* status =
-            fDecoder->decode_frame(&fPixelBuffer, fIOBuffer.reader(),
+            fDecoder->decode_frame(&fPixelBuffer, &fIOBuffer,
                                    wuffs_base__make_slice_u8(fWorkbufPtr.get(), fWorkbufLen), NULL);
         if ((status == wuffs_base__suspension__short_read) &&
             fill_buffer(&fIOBuffer, fStream.get())) {