exfat: fix misspellings using codespell tool

Sedat reported typos using codespell tool.

 $ codespell fs/exfat/*.c | grep -v iput
 fs/exfat/namei.c:293: upto ==> up to
 fs/exfat/nls.c:14: tabel ==> table

 $ codespell fs/exfat/*.h
 fs/exfat/exfat_fs.h:133: usally ==> usually

Fix typos found by codespell.

Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>