s390/pci: Remove redundant bus removal and disable from zpci_release_device()

Remove zpci_bus_remove_device() and zpci_disable_device() calls from
zpci_release_device(). These calls were done when the device
transitioned into the ZPCI_FN_STATE_STANDBY state which is guaranteed to
happen before it enters the ZPCI_FN_STATE_RESERVED state. When
zpci_release_device() is called the device is known to be in the
ZPCI_FN_STATE_RESERVED state which is also checked by a WARN_ON().

Cc: stable@vger.kernel.org
Fixes: a46044a9 ("s390/pci: fix zpci_zdev_put() on reserve")
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Reviewed-by: Julian Ruess <julianr@linux.ibm.com>
Tested-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>