Btrfs: add a flags field to btrfs_fs_info

We have a lot of random ints in btrfs_fs_info that can be put into flags.  This
is mostly equivalent with the exception of how we deal with quota going on or
off, now instead we set a flag when we are turning it on or off and deal with
that appropriately, rather than just having a pending state that the current
quota_enabled gets set to.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
index 4407fef..ca7cb5e 100644
--- a/fs/btrfs/tests/qgroup-tests.c
+++ b/fs/btrfs/tests/qgroup-tests.c
@@ -480,7 +480,7 @@
 	 */
 	root->fs_info->tree_root = root;
 	root->fs_info->quota_root = root;
-	root->fs_info->quota_enabled = 1;
+	set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
 
 	/*
 	 * Can't use bytenr 0, some things freak out