Always return 1 from x52cli for any failure

Prior to this change, on failure condition, x52cli would exit with a
code that mapped directly to the return code of the function. This was
inconsistent with the behaviour if the initialization or connect steps
failed for any reason.

cli/x52_cli.c

@@ -541,6 +541,7 @@ int main(int argc, char **argv)
     rc = (*(cmd->handler))(x52, args);
     if (rc != LIBX52_SUCCESS) {
         fprintf(stderr, "Error: %s\n", libx52_strerror(rc));
+        rc = 1;
     }
 
     libx52_update(x52);