parallels: return earlier from parallels_open() function on error

At the beginning of the function we can return immediately until we
really allocate s->header.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>

block/parallels.c

@@ -1090,7 +1090,7 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
 
     ret = bdrv_pread(bs->file, 0, sizeof(ph), &ph, 0);
     if (ret < 0) {
-        goto fail;
+        return ret;
     }
 
     bs->total_sectors = le64_to_cpu(ph.nb_sectors);
@@ -1110,30 +1110,26 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
     s->tracks = le32_to_cpu(ph.tracks);
     if (s->tracks == 0) {
         error_setg(errp, "Invalid image: Zero sectors per track");
-        ret = -EINVAL;
-        goto fail;
+        return -EINVAL;
     }
     if (s->tracks > INT32_MAX/513) {
         error_setg(errp, "Invalid image: Too big cluster");
-        ret = -EFBIG;
-        goto fail;
+        return -EFBIG;
     }
     s->prealloc_size = MAX(s->tracks, s->prealloc_size);
     s->cluster_size = s->tracks << BDRV_SECTOR_BITS;
 
     s->bat_size = le32_to_cpu(ph.bat_entries);
     if (s->bat_size > INT_MAX / sizeof(uint32_t)) {
         error_setg(errp, "Catalog too large");
-        ret = -EFBIG;
-        goto fail;
+        return -EFBIG;
     }
 
     size = bat_entry_off(s->bat_size);
     s->header_size = ROUND_UP(size, bdrv_opt_mem_align(bs->file->bs));
     s->header = qemu_try_blockalign(bs->file->bs, s->header_size);
     if (s->header == NULL) {
-        ret = -ENOMEM;
-        goto fail;
+        return -ENOMEM;
     }
 
     ret = bdrv_pread(bs->file, 0, s->header_size, s->header, 0);