staging: gpib: Fix setting controller-in-charge

staging: gpib: Fix setting controller-in-charge

The gpio board can only act as system controller.
By the IEEE488.1 standard a system controller becomes
controller-in-charge when it asserts the interface-clear control
line.

Remove the setting of controller-in-charge from bb_take_control
and move it to bb_interface_clear.

Fixes: 4cd654f84769 ("staging: gpib: Add gpio bitbang GPIB driver")
Tested-by: Dave Penkler <dpenkler@gmail.com>
Signed-off-by: Dave Penkler <dpenkler@gmail.com>
Link: https://lore.kernel.org/r/20250418173434.2892-3-dpenkler@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>