fs/fat: fix checkpatch issues in fatent.c

1: Stop any lines going over 80 characters
2: Remove a blank line before EXPORT_SYMBOL_GPL

Signed-off-by: Cruz Julian Bishop <cruzjbishop@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>