ext4: add missing brelse() for bh2 in ext4_dx_add_entry()

Add missing brelse() for bh2 in ext4_dx_add_entry().

Fixes: ac27a0ec ("[PATCH] ext4: initial copy of files from ext3")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250123162050.2114499-2-shikemeng@huaweicloud.com


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