ti_icdi: add icdi_usb_query result check

Change-Id: I0b40586677a77ee6ae46fe120a677616bde22d1e
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/1279
Tested-by: jenkins
Reviewed-by: Xiaofan <xiaofanc@gmail.com>
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>