patch 8.1.1955: tests contain typos

Problem:    Tests contain typos.
Solution:   Correct the typos. (Dominique Pelle)
diff --git a/src/testdir/test_search.vim b/src/testdir/test_search.vim
index 7c30a1a..dbe4c2a 100644
--- a/src/testdir/test_search.vim
+++ b/src/testdir/test_search.vim
@@ -267,7 +267,7 @@
   " nor "/foo\<c-u>\<cr>" works to delete the commandline.
   " In that case Vim should return "E35 no previous regular expression",
   " but it looks like Vim still sees /foo and therefore the test fails.
-  " Therefore, disableing this test
+  " Therefore, disabling this test
   "call assert_fails(feedkeys("/foo\<c-w>\<cr>", 'tx'), 'E35')
   "call assert_equal({'lnum': 1, 'leftcol': 0, 'col': 0, 'topfill': 0, 'topline': 1, 'coladd': 0, 'skipcol': 0, 'curswant': 0}, winsaveview())