ufs: fix logics in "ufs: make fsck -f happy"

Storing stats _only_ at new locations is wrong for UFS1; old
locations should always be kept updated.  The check for "has
been converted to use of new locations" is also wrong - it
should be "->fs_maxbsize is equal to ->fs_bsize".

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>