patch 8.2.3637: typos in test files

Problem:    Typos in test files.
Solution:   Correct the typos. (Dominique Pellé, closes #9175)
diff --git a/src/testdir/test_viminfo.vim b/src/testdir/test_viminfo.vim
index 6c1a711..70442ee 100644
--- a/src/testdir/test_viminfo.vim
+++ b/src/testdir/test_viminfo.vim
@@ -635,12 +635,12 @@
   call test_settime(35)
   edit again
   call test_settime(40)
-  edit fourty
+  edit forty
   wviminfo Xviminfo
 
   sp Xviminfo
   1
-  for name in ['fourty', 'again', 'thirty', 'twenty', 'ten']
+  for name in ['forty', 'again', 'thirty', 'twenty', 'ten']
     /^>
     call assert_equal(name, substitute(getline('.'), '.*/', '', ''))
   endfor
@@ -950,7 +950,7 @@
   let &viminfofile = save_vif
 endfunc
 
-" Test for an unwritable and unreadble 'viminfo' file
+" Test for an unwritable and unreadable 'viminfo' file
 func Test_viminfo_perm()
   CheckUnix
   CheckNotRoot