patch 8.1.0989: various small code ugliness

Problem:    Various small code ugliness.
Solution:   Remove pointless NULL checks. Fix function calls. Fix typos.
            (Dominique Pelle, closes #4060)
diff --git a/src/ui.c b/src/ui.c
index e21e801..5c9077c 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -1738,7 +1738,7 @@
     if (!clip_did_set_selection)
     {
 	/* Updating postponed, so that accessing the system clipboard won't
-	 * hang Vim when accessing it many times (e.g. on a :g comand). */
+	 * hang Vim when accessing it many times (e.g. on a :g command). */
 	if ((cbd == &clip_plus && (clip_unnamed_saved & CLIP_UNNAMED_PLUS))
 		|| (cbd == &clip_star && (clip_unnamed_saved & CLIP_UNNAMED)))
 	{