qseecom: Fix issues in the return path of load external elf

Fixes the issues during the return path of qseecom load external
elf function. Improper return paths are present during the error
handling cases. Wrong goto calls results in unwanted code clean-ups
which might create problems. This patch corrects the return paths
during the error cases.

Change-Id: Icd526448e7be355acb438fff600e3e85664f75f5
CRs-fixed: 498153
Signed-off-by: AnilKumar Chimata <anilc@codeaurora.org>