staging: serqt_usb2: fix dbg print when kzalloc failed to allocate qt_port

the port was kzalloced but the print statement says that its kmalloc.

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>