tests: Fix failmalloc tests

tests/nghttp2_test_helper.c

@@ -220,10 +220,10 @@ ssize_t inflate_hd(nghttp2_hd_inflater *inflater, nva_out *out,
   return processed;
 }
 
-void frame_pack_bufs_init(nghttp2_bufs *bufs)
+int frame_pack_bufs_init(nghttp2_bufs *bufs)
 {
   /* 2 for PAD_HIGH and PAD_LOW */
-  nghttp2_bufs_init2(bufs, 4096, 16, NGHTTP2_FRAME_HDLEN + 2);
+  return nghttp2_bufs_init2(bufs, 4096, 16, NGHTTP2_FRAME_HDLEN + 2);
 }
 
 void bufs_large_init(nghttp2_bufs *bufs, size_t chunk_size)

tests/nghttp2_test_helper.h

@@ -79,7 +79,7 @@ void add_out(nva_out *out, nghttp2_nv *nv);
 ssize_t inflate_hd(nghttp2_hd_inflater *inflater, nva_out *out,
                    nghttp2_bufs *bufs, size_t offset);
 
-void frame_pack_bufs_init(nghttp2_bufs *bufs);
+int frame_pack_bufs_init(nghttp2_bufs *bufs);
 
 void bufs_large_init(nghttp2_bufs *bufs, size_t chunk_size);