wireless: prism54: remove unnecessary pci_set_drvdata()

The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --cc drivers/net/wireless/prism54/islpci_dev.c
Simple merge

diff --cc drivers/net/wireless/prism54/islpci_hotplug.c
Simple merge