fix integer overflow in WIFSTOPPED macro

[musl] / arch / mips / bits / statfs.h

struct statfs {
        unsigned long f_type, f_bsize, f_frsize;
        fsblkcnt_t f_blocks, f_bfree;
        fsfilcnt_t f_files, f_ffree;
        fsblkcnt_t f_bavail;
        fsid_t f_fsid;
        unsigned long f_namelen, f_flags, f_spare[5];
};