msm: rndis_ipa: fix to debug file system init failure

Do not consider debug file system init failure as
functional failure.

Modify the code to proceed further
driver initialization.

Change-Id: I821af8970b6c2ced55d6464b8a7b56a458fa7d79
Acked-by: Javid Mohammed <mjavid@qti.qualcomm.com>
Signed-off-by: Utkarsh Saxena <usaxena@codeaurora.org>