GCC fixes for warnings

GCC was more picky about prototypes for inlines being required.

The generate_listener.py script used incorrect printf formats and
was casting %f params to float, but printf casts all %f params to
double per the spec.

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

src/platforms/posix/drivers/tonealrmsim/tone_alarm.cpp

@@ -788,7 +788,8 @@ tone_alarm_main(int argc, char *argv[])
 				PX4_WARN("not enough memory memory");
 				return 1;
 			}
-			fread(buffer, sz, 1, fd);
+			// FIXME - Make GCC happy
+			if (fread(buffer, sz, 1, fd)) { }
 			/* terminate the string */
 			buffer[sz] = 0;
 			ret = play_string(buffer, true);