patch 9.1.0942: a few typos were found

Problem:  a few typos were found
Solution: fix them (zeertzjq)

closes: #16232

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_popup.vim b/src/testdir/test_popup.vim
index 95ce561..9ea5445 100644
--- a/src/testdir/test_popup.vim
+++ b/src/testdir/test_popup.vim
@@ -1712,7 +1712,7 @@
   call StopVimInTerminal(buf)
 endfunc
 
-func Test_pum_matchins_higlight()
+func Test_pum_matchins_highlight()
   CheckScreendump
   let lines =<< trim END
     func Omni_test(findstart, base)