If "utf8" option was specified and app uses VFAT_IOCTL_READDIR_BOTH
ioctl, utf8_wcstombs() is used. utf8_wcstombs() doesn't add the nul
terminate. Then fat_ioctl_filldir() uses a wrong length of name by
strlen().

This patch passes the correct length to fat_ioctl_filldir(), and
doesn't use nul terminate anymore.

Many helps by Alex Villacís Lasso. Thanks.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>