Fix non-free'd context.

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>

src/hsm/cmd_bip_slip.c

@@ -317,8 +317,8 @@ int cmd_bip_slip() {
                                  &nodes,
                                  last_node,
                                  &hd_keytype);
-        if (r != CCID_OK) {
         mbedtls_ecp_keypair_free(&hd_context);
+        if (r != CCID_OK) {
             return SW_EXEC_ERROR();
         }
     }