We were checking whether computed offsets do not exceed end of block in
ext4_xattr_shift_entries(). However this does not make sense since we
always only decrease offsets. So replace that assertion with a check
whether we really decrease xattrs value offsets.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>