ext4: refactor ext4_free_blocks() to pull out ext4_mb_clear_bb()

stable inclusion
from stable-v5.10.175
commit 9cd21f5babb51e0eccb4bd18db890419971fe9d3
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8711T

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9cd21f5babb51e0eccb4bd18db890419971fe9d3



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

commit 8ac3939d upstream.

ext4_free_blocks() function became too long and confusing, this patch
just pulls out the ext4_mb_clear_bb() function logic from it
which clears the block bitmap and frees it.

No functionality change in this patch

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/22c30fbb26ba409cf8aa5f0c7912970272c459e8.1644992610.git.riteshh@linux.ibm.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>