f2fs: make f2fs_filetype_table static

There is no more user of f2fs_filetype_table outside of dir.c, make it
static.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 2fb20fc..39a850b 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -37,7 +37,7 @@
 		return 4;
 }
 
-unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
+static unsigned char f2fs_filetype_table[F2FS_FT_MAX] = {
 	[F2FS_FT_UNKNOWN]	= DT_UNKNOWN,
 	[F2FS_FT_REG_FILE]	= DT_REG,
 	[F2FS_FT_DIR]		= DT_DIR,