patch 8.1.1630: various small problems

Problem:    Various small problems.
Solution:   Various small improvements.
diff --git a/src/gui_beval.c b/src/gui_beval.c
index f4309b8..68d30e3 100644
--- a/src/gui_beval.c
+++ b/src/gui_beval.c
@@ -107,7 +107,7 @@
 	return NULL;
     }
 
-    beval = (BalloonEval *)alloc_clear(sizeof(BalloonEval));
+    beval = ALLOC_CLEAR_ONE(BalloonEval);
     if (beval != NULL)
     {
 #ifdef FEAT_GUI_GTK