Add guards for mbedtls_psa_crypto_free()

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/programs/fuzz/fuzz_x509csr.c b/programs/fuzz/fuzz_x509csr.c
index 6ac695f..25d68b0 100644
--- a/programs/fuzz/fuzz_x509csr.c
+++ b/programs/fuzz/fuzz_x509csr.c
@@ -19,9 +19,11 @@
     if (ret == 0) {
         ret = mbedtls_x509_csr_info((char *) buf, sizeof(buf) - 1, " ", &csr);
     }
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
 exit:
-    mbedtls_x509_csr_free(&csr);
     mbedtls_psa_crypto_free();
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+mbedtls_x509_csr_free(&csr);
 #else
     (void) Data;
     (void) Size;