audio: Use C99 initializers in read_frames()

Change-Id: I69d9ac00dbd7126682c66087804c2b33cf6c86bc
diff --git a/audio/audio_hw.c b/audio/audio_hw.c
index 6e6a71a..423ce06 100644
--- a/audio/audio_hw.c
+++ b/audio/audio_hw.c
@@ -1865,8 +1865,8 @@
                     &frames_rd);
         } else {
             struct resampler_buffer buf = {
-                    { raw : NULL, },
-                    frame_count : frames_rd,
+                    .raw = NULL,
+                    .frame_count = frames_rd,
             };
             get_next_buffer(&in->buf_provider, &buf);
             if (buf.raw != NULL) {