Rewrite some SkWuffsCodec designated initializers

This should have been part of 48aa221 "Update Wuffs version", but was
missed.

Bug: skia:8235
Bug: skia:8764
Change-Id: I3d73ca71872431955ad66d67de4166bdda0a1071
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/206141
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
diff --git a/src/codec/SkWuffsCodec.cpp b/src/codec/SkWuffsCodec.cpp
index ea5cb80..6ed45cf 100644
--- a/src/codec/SkWuffsCodec.cpp
+++ b/src/codec/SkWuffsCodec.cpp
@@ -209,13 +209,13 @@
 }
 
 SkCodec::FrameInfo SkWuffsFrame::frameInfo(bool fullyReceived) const {
-    return ((SkCodec::FrameInfo){
-        .fRequiredFrame = getRequiredFrame(),
-        .fDuration = getDuration(),
-        .fFullyReceived = fullyReceived,
-        .fAlphaType = hasAlpha() ? kUnpremul_SkAlphaType : kOpaque_SkAlphaType,
-        .fDisposalMethod = getDisposalMethod(),
-    });
+    SkCodec::FrameInfo ret;
+    ret.fRequiredFrame = getRequiredFrame();
+    ret.fDuration = getDuration();
+    ret.fFullyReceived = fullyReceived;
+    ret.fAlphaType = hasAlpha() ? kUnpremul_SkAlphaType : kOpaque_SkAlphaType;
+    ret.fDisposalMethod = getDisposalMethod();
+    return ret;
 }
 
 uint64_t SkWuffsFrame::ioPosition() const {