aes.c: remove non-functional code

Signed-off-by: Yanray Wang <yanray.wang@arm.com>
diff --git a/library/aes.c b/library/aes.c
index 29a193e..fa73a63 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -1070,7 +1070,6 @@
         return MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE;
 #endif
     }
-    return mbedtls_internal_aes_encrypt(ctx, input, output);
 #endif /* !MBEDTLS_AES_USE_HARDWARE_ONLY */
 }