math: fix two fma issues (only affects non-nearest rounding mode, x86)

[musl] / src / thread / pthread_mutexattr_setrobust.c

#include "pthread_impl.h"

int pthread_mutexattr_setrobust(pthread_mutexattr_t *a, int robust)
{
        if (robust > 1U) return EINVAL;
        *a &= ~4;
        *a |= robust*4;
        return 0;
}