Wipe output buffer even when INCOMPLETE is returned.

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 776a9c8..e10c34c 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -3292,10 +3292,10 @@
     /* Update ops count with work done. */
     operation->num_ops = psa_driver_wrapper_sign_hash_get_num_ops(operation);
 
-    if (status != PSA_OPERATION_INCOMPLETE) {
-        psa_wipe_output_buffer(signature, status, signature_size,
-                               *signature_length);
+    psa_wipe_output_buffer(signature, status, signature_size,
+                           *signature_length);
 
+    if (status != PSA_OPERATION_INCOMPLETE) {
         if (status != PSA_SUCCESS) {
             operation->error_occurred = 1;
         }