usb: typec: intel_pmc_mux: Handle SCU IPC error conditions

usb: typec: intel_pmc_mux: Handle SCU IPC error conditions

Check and return if there are errors. The response bits are valid
only on no errors.

Fixes: c47c01ff48b0 ("usb: typec: intel_pmc_mux: Definitions for response status bits")
Signed-off-by: Madhusudanarao Amara <madhusudanarao.amara@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20200916091102.27118-4-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>