The low byte of FAT's first entry must have same value with media-field.

So, I added that validity check for some case. In fact, in some case
this check detected non-FAT filesystem.  But in real world,
unfortunately too many devices is writing a wrong value.

This patch removes that validity check.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>