Change psa_crypto_copy_output error code

When we are copying output, it makes sense to return
PSA_ERROR_BUFFER_TOO_SMALL since the buffer we are copying to is a user
output buffer.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 0679368..b3bb394 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -5558,7 +5558,7 @@
  * \param[out] output_len       Length of the user-supplied output buffer.
  * \return                      #PSA_SUCCESS, if the buffer was successfully
  *                              copied.
- * \return                      #PSA_ERROR_CORRUPTION_DETECTED, if the
+ * \return                      #PSA_ERROR_BUFFER_TOO_SMALL, if the
  *                              user-supplied output buffer is too small to
  *                              hold the contents of the local buffer.
  */
@@ -5567,7 +5567,7 @@
                                     uint8_t *output, size_t output_len)
 {
     if (output_len < output_copy_len) {
-        return PSA_ERROR_CORRUPTION_DETECTED;
+        return PSA_ERROR_BUFFER_TOO_SMALL;
     }
 
     if (output_copy_len > 0) {