[tpm2-tss] Allocate memory inside the tpm2-tss TCTI stack.

This change corrects an error where the allocation wasn't actually
being performed in the Fuchsia_Init_Ex function. This internal
allocation is required so that malloc/free operate correctly
with the finalize function.

Change-Id: Ie11598dfff18dbe08c0d3c4b58e545d695c81e25
diff --git a/src/tss2-tcti/tcti-fuchsia.c b/src/tss2-tcti/tcti-fuchsia.c
index 44bea08..201c083 100644
--- a/src/tss2-tcti/tcti-fuchsia.c
+++ b/src/tss2-tcti/tcti-fuchsia.c
@@ -234,6 +234,7 @@
     if (rc != TSS2_RC_SUCCESS) {
         return rc;
     }
+    *tctiContext = (TSS2_TCTI_CONTEXT*)calloc(1, context_size);
     rc = Tss2_Tcti_Fuchsia_Init(*tctiContext, &context_size, conf);
     if (rc != TSS2_RC_SUCCESS) {
         return rc;