msm: ipc: Clean-up code redundancy

The receive message operation for the socket interface and the kernel
interface has redundant code.

Clean-up redundant code.

Change-Id: Ibe52816f5b567feab4d6247a3dba1945e209c626
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>