ext4: call journal revoke when freeing ea_inode blocks

ea_inode contents are treated as metadata, that's why it is journaled
during initial writes. Failing to call revoke during freeing could cause
user data to be overwritten with original ea_inode contents during journal
replay.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>