Add guards for mbedtls_psa_crypto_free()

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/programs/fuzz/fuzz_x509crt.c b/programs/fuzz/fuzz_x509crt.c
index 157456c..8442090 100644
--- a/programs/fuzz/fuzz_x509crt.c
+++ b/programs/fuzz/fuzz_x509crt.c
@@ -26,9 +26,12 @@
     ((void) ret);
     ((void) buf);
 #endif /* !MBEDTLS_X509_REMOVE_INFO */
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
 exit:
-    mbedtls_x509_crt_free(&crt);
     mbedtls_psa_crypto_free();
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+    mbedtls_x509_crt_free(&crt);
 #else
     (void) Data;
     (void) Size;