cxgb4: Fix offset when clearing filter byte counters

[ Upstream commit 94cc242a067a869c29800aa789d38b7676136e50 ]

Pass the correct offset to clear the stale filter hit
bytes counter. Otherwise, the counter starts incrementing
from the stale information, instead of 0.

Fixes: 12b276fb ("cxgb4: add support to create hash filters")
Signed-off-by: Ganji Aravind <ganji.aravind@chelsio.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>