Fix typos in README files. (Dominique Pelle)
diff --git a/README_os390.txt b/README_os390.txt
index 20f4989..366ec34 100644
--- a/README_os390.txt
+++ b/README_os390.txt
@@ -3,7 +3,7 @@
 This readme explains how to build Vim on z/OS.  Formerly called OS/390.
 See "README.txt" for general information about Vim.
 
-Most likley there are not many users out there using Vim on z/OS. So chances
+Most likely there are not many users out there using Vim on z/OS. So chances
 are good, that some bugs are still undiscovered.
 
 Getting the source to z/OS: