fpga: bridge: Replace open-coded list_for_each + list_entry

Replaces open-coded list_for_each() + list_entry() with macro
list_for_each_entry()

Signed-off-by: Moritz Fischer <mdf@kernel.org>
Cc: linux-fpga@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>