usb: composite: don't print the invalid function wakeup failure messages

The function level suspend/resume/wakeup are supported in super speed
mode only. The usb_func_wakeup() is called for every function during
resume irrespective of the operating speed. This function returns
-ENOTSUPP when the gadget is not operating in super speed. Don't print
the error message in this case. Otherwise an error message is printed
for each function during high/full speed device resume.

CRs-Fixed: 750230
Change-Id: I6f600fe7fa9a037b83909265229acdc668329d6a
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>