MFC r289687,r289693:

r289687:

Free buffer before returning from cd9660_write_path_table to avoid
leaking it after returning from the function

PR: 203647
Submitted by: Thomas Schmitt <scdbackup@gmx.net>
Coverity CID: 978431
Sponsored by: EMC / Isilon Storage Division

r289693:

Unbreak makefs -t cd9660 after r289687

buffer_head needs to be freed -- not buffer

Detected by jemalloc, i.e. running makefs failed the arena assert
because my copy of malloc on CURRENT is compiled with the default
!MALLOC_PRODUCTION asserts on

Pointyhat to: ngie
PR: 203647
Sponsored by: EMC / Isilon Storage Division