Conditionally include exit label

...on functions where the label was only added
due to the modifications required by this PR.

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 2a52daa..183b4a1 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -2631,7 +2631,9 @@
         psa_mac_abort(operation);
     }
 
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
 exit:
+#endif
     LOCAL_INPUT_FREE(input_external, input);
 
     return status;
@@ -2813,7 +2815,10 @@
     status = psa_mac_compute_internal(key, alg,
                                     input, input_length,
                                     mac, mac_size, mac_length, 1);
+
+#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
 exit:
+#endif
     LOCAL_INPUT_FREE(input_external, input);
     LOCAL_OUTPUT_FREE(mac_external, mac);