msm: rpm-smd: Fix uninitialized variables in a function

The return variables in certain variables were uninitiliazed and can
lead to unknown behavior when the caller deferences them.

Change-Id: Ifa92c8f2e2ea1a65940995a124a6c7f198337414
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>