sound: usb: move debug logging in uaudio_qmi_svc_disconnect_cb function

Debug log in uaudio_qmi_svc_disconnect_cb() function can be printed
if the driver debug logs are enabled by default. Move debug log
further in disconnect function. This will avoid printing
unnecessary log messages in dmesg/console.

Change-Id: I4c1ea526861c2a3353e724e2d9a2bf535d051cc9
Signed-off-by: Chandana Kishori Chiluveru <cchiluve@codeaurora.org>