f2fs-tools: add cscope files to .gitignore

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/.gitignore b/.gitignore
index abe1336..d5ca55d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -50,3 +50,7 @@
 /tools/fibmap.f2fs
 /tools/parse.f2fs
 /tools/f2fscrypt
+
+# cscope files
+cscope.*
+ncscope.*