soc: qcom: Fix presence of garbage value in 32 msb of smcinvoke_obj->fd

The function get_uhandle_from_tzhandle is passed a temporary
fd of type int32_t instead of passing a typecasted
smcinvoke_obj->fd which of type int64_t. This will prevent any
garbage value to remain in 32 msb after successful creation
of the new fd.

Change-Id: I695a85fd7762f7eca0d46721ac60c8cd1b59f163
Signed-off-by: Pranay Raj Anand <prajanan@codeaurora.org>