reiserfs: use proper little-endian bitops

Using __test_and_{set,clear}_bit_le() with ignoring its return value can
be replaced with __{set,clear}_bit_le().

This introduces reiserfs_{set,clear}_le_bit for __{set,clear}_bit_le and
does the above change with them.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>