patch 8.2.2160: various typos

Problem:    Various typos.
Solution:   Fix spelling mistakes. (closes #7494)
diff --git a/src/userfunc.c b/src/userfunc.c
index 2d71a7f..50088e6 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -1409,7 +1409,7 @@
 
 /*
  * Restore the function call depth.  This is for cases where there is no
- * garantee funcdepth_decrement() can be called exactly the same number of
+ * guarantee funcdepth_decrement() can be called exactly the same number of
  * times as funcdepth_increment().
  */
     void