Some systems seem to pick up the kernel definitions, so check
if __must_check is defined before (potentially) redefining it.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
#define FIO_COMPILER_GCC3_H
#if __GNUC_MINOR__ >= 4
#define FIO_COMPILER_GCC3_H
#if __GNUC_MINOR__ >= 4
#define __must_check __attribute__((warn_unused_result))
#endif
#define __must_check __attribute__((warn_unused_result))
#endif
#ifndef FIO_COMPILER_GCC4_H
#define FIO_COMPILER_GCC4_H
#ifndef FIO_COMPILER_GCC4_H
#define FIO_COMPILER_GCC4_H
#define __must_check __attribute__((warn_unused_result))
#define __must_check __attribute__((warn_unused_result))