selftests: mlxsw: sch_red_core: Drop two unused variables

These variables are cut'n'pasted from other functions in the file and not
actually used.
Signed-off-by: NPetr Machata <petrm@nvidia.com>
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tools/testing/selftests/drivers/net/mlxsw/sch_red_core.sh

@@ -551,10 +551,8 @@ do_drop_test()
 	local trigger=$1; shift
 	local subtest=$1; shift
 	local fetch_counter=$1; shift
-	local backlog
 	local base
 	local now
-	local pct
 
 	RET=0