USB: Debugfs: Fix compilation issues when debugfs is disabled

When we disable debugfs some of the function driver does not
handle those error properly so we see error of kind variable
undeclared, too many arguements to function. This fixes all
these obseved issue

Change-Id: I1b60c86b1c489f77edf86a5df44f8766a08dc117
CRs-fixed: 551713
Signed-off-by: Tarun Gupta <tarung@codeaurora.org>