ext4: factor out ext4_percpu_param_init() and ext4_percpu_param_destroy()

Factor out ext4_percpu_param_init() and ext4_percpu_param_destroy(). And
also use ext4_percpu_param_destroy() in ext4_put_super() to avoid
duplicated code. No functional change.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20230323140517.1070239-3-yanaijie@huawei.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>