wolfcrypt/test/test.c: add missing PRIVATE_KEY_UNLOCK() for hpke_test().

Author: douzzer

wolfcrypt/test/test.c

@@ -1767,10 +1767,12 @@ options: [-s max_relative_stack_bytes] [-m max_relative_heap_memory_bytes]\n\
 #endif
 
 #if defined(HAVE_HPKE) && defined(HAVE_ECC) && defined(HAVE_AESGCM)
+    PRIVATE_KEY_UNLOCK();
     if ( (ret = hpke_test()) != 0)
         TEST_FAIL("HPKE     test failed!\n", ret);
     else
         TEST_PASS("HPKE     test passed!\n");
+    PRIVATE_KEY_LOCK();
 #endif
 
 #if defined(WC_SRTP_KDF)