Clarify the two error cases on powerpc64.
On 13 the entire output is:
ninja: build stopped: subcommand failed.
Traceback (most recent call last):
File "build_mozc.py", line 1272, in <module>
main()
File "build_mozc.py", line 1259, in main
BuildMain(cmd_opts, cmd_args)
File "build_mozc.py", line 890, in BuildMain
BuildWithNinja(options, targets)
File "build_mozc.py", line 864, in BuildWithNinja
RunOrDie([ninja, '-v', '-C', build_arg] + ninja_targets)
File "/wrkdirs/usr/ports/japanese/mozc-server/work/mozc-2.23.2815.102.00/src/build_tools/util.py", line 99, in RunOrDie
'==========']))
build_tools.util.RunOrDieError:
==========
ERROR: ninja -v -C out_linux/Release mozc_server
==========
*** Error code 1
Approved by: portmgr (tier-2 blanket)