Add missing 'n'.

Thanks to Han Finkel for noticing it.

llvm-svn: 187241
diff --git a/llvm/lib/Support/Unix/Program.inc b/llvm/lib/Support/Unix/Program.inc
index 0605d53..a93a912 100644
--- a/llvm/lib/Support/Unix/Program.inc
+++ b/llvm/lib/Support/Unix/Program.inc
@@ -186,7 +186,7 @@
     posix_spawn_file_actions_t *FileActions = 0;
 
     // If we call posix_spawn_file_actions_addopen we have to make sure the
-    // c strings we pass to it stay alive until the call to posix_spaw,
+    // c strings we pass to it stay alive until the call to posix_spawn,
     // so we copy any StringRefs into this variable.
     std::string RedirectsStorage[3];