patch 8.2.4649: various formatting problems

Problem:    Various formatting problems.
Solution:   Improve the code formatting.
diff --git a/src/os_unix.c b/src/os_unix.c
index 5b516e0..826c9c0 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -3762,7 +3762,7 @@
 static int	mouse_ison = FALSE;
 
 /*
- * Set mouse clicks on or off.
+ * Set mouse clicks on or off and possible enable mouse movement events.
  */
     void
 mch_setmouse(int on)