bcachefs: -EROFS doesn't count as move_extent_start_fail

The automated tests check if we've hit too many slowpath/error path
events and fail the test - if we're just shutting down, that naturally
shouldn't count.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/move.c

@@ -338,6 +338,10 @@ int bch2_move_extent(struct moving_context *ctxt,
 	if (ret == -BCH_ERR_data_update_done)
 		return 0;
 
+	if (bch2_err_matches(ret, EROFS) ||
+	    bch2_err_matches(ret, BCH_ERR_transaction_restart))
+		return ret;
+
 	this_cpu_inc(c->counters[BCH_COUNTER_move_extent_start_fail]);
 	if (trace_move_extent_start_fail_enabled()) {
 		struct printbuf buf = PRINTBUF;