audio/alsaaudio: Remove compiler check around pragma

Both GCC v4.8 and Clang v3.4 support the -Waddress option, so we do
not need the compiler version check here anymore.
Reviewed-by: NRichard Henderson <richard.henderson@linaro.org>
Signed-off-by: NThomas Huth <thuth@redhat.com>

audio/alsaaudio.c

@@ -28,9 +28,7 @@
 #include "audio.h"
 #include "trace.h"
 
-#if QEMU_GNUC_PREREQ(4, 3)
 #pragma GCC diagnostic ignored "-Waddress"
-#endif
 
 #define AUDIO_CAP "alsa"
 #include "audio_int.h"