USB: fix usbatm tiny race

ia64:

drivers/usb/atm/usbatm.c: In function `usbatm_do_heavy_init':
drivers/usb/atm/usbatm.c:1004: warning: implicit declaration of function `get_current'
drivers/usb/atm/usbatm.c:1004: error: invalid type argument of `->'

Signed-off-by: Duncan Sands <baldrick@free.fr>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>