Correct comments in testdir makefiles. (John Beckett)
diff --git a/src/testdir/Make_os2.mak b/src/testdir/Make_os2.mak
index ccbdb3e..f5262e2 100644
--- a/src/testdir/Make_os2.mak
+++ b/src/testdir/Make_os2.mak
@@ -1,5 +1,5 @@
 #
-# Makefile to run al tests for Vim, on OS/2
+# Makefile to run all tests for Vim, on OS/2
 #
 # Requires a set of Unix tools: echo, diff, etc.