net: usb: Continue submitting rx URBs upon QMI channel close

If user space consumer of QMI channels restarts, channels get closed
and opened again. Closing QMI channel stops submitting rx URBs which
is not getting re-submitted during channel open. Since userspace
consumer automatically restarts in case if it gets killed, do not kill
the rx URBs upon channel close.

CRs-Fixed: 370712
Change-Id: Ia58aaefd5245b07640fe2ec5eb2ec5fe1ae43cd4
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>