usb: ks_bridge: Check for received data upon unlinking the urb

There is a possibility of runtime suspend in the middle of
data transfer on the rx data path of driver. This results in
the completion of data transfer on bulk IN endpoint with short
packet or integral multiple of 512 bytes. Hence for -ENOENT
transfer status check for non-zero data length and pass it to
the consumer in the userspace. Also, replace printk with
DBG-level message in driver suspend function and in rx
callback function for -EPROTO urb status.

CRs-Fixed: 394954
Change-Id: I26f4081869377000d163649b3a860386ff9c3806
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>