fsmonitor: trace the new invalidated cache-entry count

Consolidate the directory/non-directory calls to the refresh handler
code.  Log the resulting count of invalidated cache-entries.

The nr_in_cone value will be used in a later commit to decide if
we also need to try to do case-insensitive lookups.

Signed-off-by: Jeff Hostetler <jeffhostetler@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

fsmonitor.c

@@ -308,16 +308,21 @@ static void fsmonitor_refresh_callback(struct index_state *istate, char *name)
 {
 	int len = strlen(name);
 	int pos = index_name_pos(istate, name, len);
+	size_t nr_in_cone;
 
 	trace_printf_key(&trace_fsmonitor,
 			 "fsmonitor_refresh_callback '%s' (pos %d)",
 			 name, pos);
 
-	if (name[len - 1] == '/') {
-		handle_path_with_trailing_slash(istate, name, pos);
-	} else {
-		handle_path_without_trailing_slash(istate, name, pos);
-	}
+	if (name[len - 1] == '/')
+		nr_in_cone = handle_path_with_trailing_slash(istate, name, pos);
+	else
+		nr_in_cone = handle_path_without_trailing_slash(istate, name, pos);
+
+	if (nr_in_cone)
+		trace_printf_key(&trace_fsmonitor,
+				 "fsmonitor_refresh_callback CNT: %d",
+				 (int)nr_in_cone);
 }
 
 /*