Added -Wno-tautological-compare to voice_engine

Added -Wno-tautological-compare to voice_engine

LOG_F generates warning with some severity setting.

[ckulakowski, 2015-07-07 09:54:19]

ckulakowski@opera.com changed reviewers:
+ kjellander@webrtc.org

[ckulakowski, 2015-07-07 09:55:07]

Without this compilation parameter LOG_F generates warning with some severity
setting.

[ckulakowski, 2015-07-07 09:56:39]

On 2015/07/07 09:55:07, ckulakowski wrote:
> Without this compilation parameter LOG_F generates warning with some severity
> setting.

To be more exact: LOG_F generates warning "self-comparison always evaluates to
false".

[kjellander, 2015-07-07 11:14:43]

On 2015/07/07 09:56:39, ckulakowski wrote:
> On 2015/07/07 09:55:07, ckulakowski wrote:
> > Without this compilation parameter LOG_F generates warning with some
severity
> > setting.
> 
> To be more exact: LOG_F generates warning "self-comparison always evaluates to
> false".

Please update your checkout and create a new CL on https://codereview.webrtc.org
instead. Then please pick henrikg@webrtc.org or henrika@webrtc.org as reviewer
as I'm OOO for 8 more weeks.

[ajm, 2015-07-07 17:18:09]

andrew@webrtc.org changed reviewers:
+ andrew@webrtc.org

[ajm, 2015-07-07 17:18:09]

Drive-by.

https://webrtc-codereview.appspot.com/54789004/diff/1/voice_engine/voice_engi...
File voice_engine/voice_engine.gyp (right):

https://webrtc-codereview.appspot.com/54789004/diff/1/voice_engine/voice_engi...
voice_engine/voice_engine.gyp:32: '-Wno-tautological-compare',
Is it possible to fix the LOG_F macro instead?

[bratell at opera, 2015-09-11 07:54:01]

On 2015/07/07 17:18:09, ajm wrote:
> Drive-by.
> 
>
https://webrtc-codereview.appspot.com/54789004/diff/1/voice_engine/voice_engi...
> File voice_engine/voice_engine.gyp (right):
> 
>
https://webrtc-codereview.appspot.com/54789004/diff/1/voice_engine/voice_engi...
> voice_engine/voice_engine.gyp:32: '-Wno-tautological-compare',
> Is it possible to fix the LOG_F macro instead?

I guess the problem is RESTRICT_LOGGING_PRECONDITION(sev) which expands to

"sev < webrtc::LS_INFO ? (void) 0 :"

This doesn't seem that strange except for the two-thirds of a tertiary
condition. Maybe that is why the compiler warns here and not everywhere. Or
maybe everywhere else uses the flag this patch is adding.