gitignore: Add a ctags generated file

Signed-off-by: Petr Vorel <pvorel@suse.cz>
diff --git a/.gitignore b/.gitignore
index cbaea66..6d57825 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,6 +30,7 @@
 /execltp
 /ltp-devel.spec
 /README.ltp-devel
+/tags
 /Version
 /include/mk/config.mk
 /include/mk/config-openposix.mk