patch 8.1.2243: typos in comments

Problem:    Typos in comments.
Solution:   Fix the typos. (Dominique Pelle, closes #5160)  Also adjust
            formatting a bit.
diff --git a/src/ui.c b/src/ui.c
index 0170df7..2d33f7b 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -913,7 +913,7 @@
 
     if (clip_did_set_selection)
     {
-	clip_unnamed = FALSE;
+	clip_unnamed = 0;
 	clip_did_set_selection = FALSE;
     }
 }
@@ -941,7 +941,7 @@
     {
 	clip_did_set_selection = TRUE;
 	clip_unnamed = clip_unnamed_saved;
-	clip_unnamed_saved = FALSE;
+	clip_unnamed_saved = 0;
 	if (clipboard_needs_update)
 	{
 	    /* only store something in the clipboard,