patch 8.2.1547: various comment problems

Problem:    Various comment problems.
Solution:   Update comments.
diff --git a/src/arglist.c b/src/arglist.c
index 1810367..ab23880 100644
--- a/src/arglist.c
+++ b/src/arglist.c
@@ -778,7 +778,7 @@
 
     if (eap->addr_count > 0 || *eap->arg == NUL)
     {
-	// ":argdel" works like ":argdel"
+	// ":argdel" works like ":.argdel"
 	if (eap->addr_count == 0)
 	{
 	    if (curwin->w_arg_idx >= ARGCOUNT)