adb, convndx: check istream_close result

src/adb.c

@@ -966,8 +966,7 @@ int adb_c_block_data(struct apk_ostream *os, apk_blob_t hdr, uint32_t size, stru
 		if (r < 0) return r;
 	}
 
-	apk_istream_close(is);
-	return 0;
+	return apk_istream_close(is);
 }
 
 int adb_c_block_copy(struct apk_ostream *os, struct adb_block *b, struct apk_istream *is, struct adb_verify_ctx *vfy)

src/app_convndx.c

@@ -43,7 +43,7 @@ static int load_apkindex(void *sctx, const struct apk_file_info *fi,
 	if (strcmp(fi->name, "APKINDEX") == 0) {
 		ctx->found = 1;
 		convert_index(ctx, is);
-		apk_istream_close(is);
+		return apk_istream_close(is);
 	}
 
 	return 0;