patch 8.2.2160: various typos

Problem:    Various typos.
Solution:   Fix spelling mistakes. (closes #7494)
diff --git a/src/testdir/test_menu.vim b/src/testdir/test_menu.vim
index 033d428..3df1560 100644
--- a/src/testdir/test_menu.vim
+++ b/src/testdir/test_menu.vim
@@ -426,7 +426,7 @@
   nunmenu Test.Sign
 endfunc
 
-" Test for "icon=filname" in a toolbar
+" Test for "icon=filename" in a toolbar
 func Test_menu_icon()
   CheckFeature toolbar
   nmenu icon=myicon.xpm Toolbar.Foo  :echo "Foo"<CR>