Whitespace cleanup: Remove all multiple newlines

This patch removes all occurrences of double and triple
newlines.

Command used for this:
find .  -type d \( -name ffmpeg \) -prune -o \
        -regex '\(.*\.[hc]\|.*\.cc\)' \
        -a -not -name 'adrian-aec.*' -a -not \
        -name reserve.c -a -not -name 'rtkit.*' \
        -exec sed -i -e '/^$/{N;s/^\n$//}' {} \;

Two passes were needed to remove triple newlines.
The excluded files are mirrored files from external sources.

src/pulse/channelmap.c

@@ -392,7 +392,6 @@ pa_channel_map* pa_channel_map_init_auto(pa_channel_map *m, unsigned channels, p
                     return NULL;
             }
 
-
         default:
             pa_assert_not_reached();
     }