Fix some compiler warnings
tests: Fix -Wodr warning compiling tests with LTO enabled
Avoid the compiler to see 2 different defines of the same structure.
Also removes:
In function ‘stream_channel_get_supported_codecs’,
inlined from ‘on_connect’ at ../server/stream-channel.cpp:364:60:
../server/stream-channel.cpp:326:31: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=]
326 | out_codecs[num++] = codec;
| ^
../server/stream-channel.cpp: In member function ‘on_connect’:
/usr/include/spice-1/spice/stream-device.h:209:13: note: destination object ‘codecs’ of size 0
209 | uint8_t codecs[0];
| ^
Reported by Tomasz Kłoczko in #44 (closed)
Edited by Frediano Ziglio