soc: qcom: smem: Fix uninitialized usage of a stack variable

variable size is output variable and is not initialized,
printing it can lead to information leak.

variable size is removed from log message.

CRs-Fixed: 1093837
Change-Id: I95cf227bb82a2ee7c6f43db151f75a942e8e55ce
Signed-off-by: Dhoat Harpal <hdhoat@codeaurora.org>