patch 9.0.1453: typos in source code and tests

Problem:    Typos in source code and tests.
Solution:   Fi the typos. (Dominique Pellé, closes #12217)
diff --git a/src/if_ole.cpp b/src/if_ole.cpp
index 9dc15fd..f347387 100644
--- a/src/if_ole.cpp
+++ b/src/if_ole.cpp
@@ -334,7 +334,7 @@
     /* Reject strings too long to fit in the input buffer. Allow 10 bytes
      * space to cover for the (remote) possibility that characters may enter
      * the input buffer between now and when the WM_OLE message is actually
-     * processed. If more that 10 characters enter the input buffer in that
+     * processed. If more than 10 characters enter the input buffer in that
      * time, the WM_OLE processing will simply fail to insert the characters.
      */
     if ((int)(STRLEN(str)) > (vim_free_in_input_buf() - 10))