block: Remove bdrv_is_snapshot

This is unnecessary and has been unused since 5433c24f.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block.c

@@ -3013,11 +3013,6 @@ bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
     return false;
 }
 
-int bdrv_is_snapshot(BlockDriverState *bs)
-{
-    return !!(bs->open_flags & BDRV_O_SNAPSHOT);
-}
-
 /* backing_file can either be relative, or absolute, or a protocol.  If it is
  * relative, it must be relative to the chain.  So, passing in bs->filename
  * from a BDS as backing_file should not be done, as that may be relative to

include/block/block.h

@@ -414,7 +414,6 @@ void bdrv_get_full_backing_filename_from_filename(const char *backed,
                                                   const char *backing,
                                                   char *dest, size_t sz,
                                                   Error **errp);
-int bdrv_is_snapshot(BlockDriverState *bs);
 
 int path_has_protocol(const char *path);
 int path_is_absolute(const char *path);