examples/native: flush unused EK before CreateLoaded

native_test creates an EK primary and an SRK primary, then calls
TPM2_CreateLoaded under the SRK. The EK is unused between creation
and the common cleanup path, so it just sits in TPM object memory.
On TPMs with tight transient-object limits (Nations NS350 at
RSA-4096 only holds two transient objects), the third object made
by CreateLoaded returns TPM_RC_OBJECT_MEMORY.

Flush the EK right after the SRK is created. No behavior change on
TPMs with spare object memory; fixes the OOM on constrained parts.

Author: aidangarske

examples/native/native_test.c

@@ -1055,6 +1055,16 @@ int TPM2_Native_TestArgs(void* userCtx, int argc, char *argv[])
     printf("TPM2_CreatePrimary: Storage 0x%x (%d bytes)\n",
         (word32)storage.handle, storage.pub.size);
 
+    /* Flush EK now to free a transient slot. Smaller-memory TPMs (e.g.
+     * Nations NS350 at RSA-4096) can only hold 2 transient objects, so
+     * keeping EK loaded would OOM on the next CreateLoaded. EK isn't used
+     * again until the common cleanup path, so drop it here. */
+    if (endorse.handle != TPM_RH_NULL) {
+        cmdIn.flushCtx.flushHandle = endorse.handle;
+        TPM2_FlushContext(&cmdIn.flushCtx);
+        endorse.handle = TPM_RH_NULL;
+    }
+
 #if 0
     /* Move new primary key into NV to persist */
     cmdIn.evict.auth = endorse.handle;