image: Update zstd to avoid reporting error twice

The zstd implementation prints the error in image_decomp() which is
incorrect and does not match other algorithms. Drop this and let the
caller report the error.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/image.c b/common/image.c
index 1102483..62314a9 100644
--- a/common/image.c
+++ b/common/image.c
@@ -534,12 +534,10 @@
 		abuf_init_set(&in, image_buf, image_len);
 		abuf_init_set(&in, load_buf, unc_len);
 		ret = zstd_decompress(&in, &out);
-		if (ret < 0) {
-			printf("ZSTD decompression failed\n");
-			return ret;
+		if (ret >= 0) {
+			image_len = ret;
+			ret = 0;
 		}
-
-		image_len = ret;
 		break;
 	}
 #endif /* CONFIG_ZSTD */