ext4: fix iloc.bh leak in ext4_fc_replay_inode() error paths

In the Linux kernel, the following vulnerability has been resolved:

ext4: fix iloc.bh leak in ext4_fc_replay_inode() error paths

During code review, Joseph found that ext4_fc_replay_inode() calls

ext4_get_fc_inode_loc() to get the inode location, which holds a

reference to iloc.bh that must be released via brelse().

However, several error paths jump to the 'out' label without

releasing iloc.bh:

- ext4_handle_dirty_metadata() failure

- sync_dirty_buffer() failure

- ext4_mark_inode_used() failure

- ext4_iget() failure

Fix this by introducing an 'out_brelse' label placed just before

the existing 'out' label to ensure iloc.bh is always released.

Additionally, make ext4_fc_replay_inode() propagate errors

properly instead of always returning 0.