ext4: force overhead calculation if the s_overhead_cluster makes no sense

stable inclusion
from stable-4.19.240
commit 92d2d51544468a7b378a7213c0c27202f3e1b7c1
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5A6BA


CVE: NA

--------------------------------

commit 85d825db upstream.

If the file system does not use bigalloc, calculating the overhead is
cheap, so force the recalculation of the overhead so we don't have to
trust the precalculated overhead in the superblock.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>