fat: fix build warning

This fixes a compile warning (unititialized variable) in
the fat filesystem code.

Signed-off-by: Jonas Aberg <jonas.aberg@stericsson.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>

fs/fat/dir.c

@@ -1231,7 +1231,7 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots,
 	struct super_block *sb = dir->i_sb;
 	struct msdos_sb_info *sbi = MSDOS_SB(sb);
 	struct buffer_head *bh, *prev, *bhs[3]; /* 32*slots (672bytes) */
-	struct msdos_dir_entry *de;
+	struct msdos_dir_entry *uninitialized_var(de);
 	int err, free_slots, i, nr_bhs;
 	loff_t pos, i_pos;