[POWERPC] pseries: Fix jumbled no_logging flag

Get rid of the jumbled usage of the no_logging flag. Its use
spans several directories, and is incorrectly/misleadingly
documented. Instead, two changes:
1) nvram will accept error log as soon as its ready.
2) logging to nvram stops on the first fatal error reported.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
----
 arch/powerpc/kernel/nvram_64.c         |    8 --------
 arch/powerpc/platforms/pseries/rtasd.c |   14 ++++++--------
 2 files changed, 6 insertions(+), 16 deletions(-)
Signed-off-by: Paul Mackerras <paulus@samba.org>