msm: kgsl: Fix an uninitialized variable warning

Some compilers hit on an uninitalized variable warning in _load_regfile().
Personally, I don't see it but who am I to question the great wisdom
of the mighty GCC?

Change-Id: Ic0dedbad5a3e0eb66c4c17bc8a5129b812a4febc
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>