do not display ENOENT errors when opening a non-existent file

the intent of 6e85f17 was to show errors like `EPERM`. it's a common
practice to start the editor with a filename that doesn't exist yet,
in which case you get `ENOENT`. so let's just not display an error in
that case.

Author: adsr

bview.c

@@ -791,7 +791,7 @@ static buffer_t *_bview_open_buffer(bview_t *self, char *opt_path, int opt_path_
     if (!buffer) {
         buffer = buffer_new();
         if (has_path) buffer->path = strndup(opt_path, opt_path_len);
-        if (buffer_errno != 0) {
+        if (buffer_errno != 0 && buffer_errno != ENOENT) {
             MLE_SET_ERR(self->editor, "_bview_open_buffer: %s", strerror(buffer_errno));
         }
     }