btrfs: check qgroup on extent de-reference

Test if qgroup can handle extent de-reference during reallocation.
"extent de-reference" means that reducing an extent's reference
count or freeing an extent.

Although current qgroup can handle it, we still need to prevent any
regression which may break current qgroup.

Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

common/rc

@@ -3285,9 +3285,9 @@ _btrfs_get_profile_configs()
 # stress btrfs by running balance operation in a loop
 _btrfs_stress_balance()
 {
-	local btrfs_mnt=$1
+	local options=$@
 	while true; do
-		$BTRFS_UTIL_PROG balance start $btrfs_mnt
+		$BTRFS_UTIL_PROG balance start $options
 	done
 }