e2fsck: update quota when deallocating a bad inode

e2fsck: update quota when deallocating a bad inode

If a bad inode is found it will be deallocated.  However, if the filesystem has
quota enabled, the quota information isn't being updated accordingly.  This
issue was detected by running fstest ext4/019.

This patch fixes the issue by decreasing the inode count from the
quota and, if blocks are also being released, also subtract them as well.

While there, and as suggested by Andreas Dilger, the deallocate_inode()
function documentation is also updated by this patch to make it clear what
that function really does.

Signed-off-by: Luis Henriques (SUSE) <luis.henriques@linux.dev>
Link: https://lore.kernel.org/r/20240405142405.12312-3-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o <tytso@mit.edu>