usb: qcserial add missing errorpath kfrees

There are two -ENODEV error paths in qcprobe where the allocated private
data is not freed, this patch adds the two missing kfrees to avoid
leaking memory on the error path

Signed-off-by: Steven Hardy <shardy@redhat.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>