If we chose to "do_more", we would double-count the amount freed in the
second and subsequent block groups.  Fix it the same way as was done in
ext2 a couple of years ago.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>