`test_uptime::test_uptime_with_file_containing_valid_boot_time_utmpx_record stdout` fails on linux arm64

[sylvestre]

See:
#7153

---- test_uptime::test_uptime_with_file_containing_valid_boot_time_utmpx_record stdout ----
run: /home/runner/work/coreutils/coreutils/target/aarch64-unknown-linux-gnu/debug/coreutils uptime testx
thread 'test_uptime::test_uptime_with_file_containing_valid_boot_time_utmpx_record' panicked at tests/by-util/test_uptime.rs:116:10:
Command was expected to succeed. code: 101
stdout =  09:22:30  
 stderr = thread 'main' panicked at src/uucore/src/lib/features/utmpx.rs:190:31:
attempt to multiply with overflow
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

stack backtrace:
   0: rust_begin_unwind
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/std/src/panicking.rs:652:5
   1: core::panicking::panic_fmt
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/panicking.rs:72:14
   2: tests::common::util::CmdResult::success
             at ./tests/common/util.rs:417:9
   3: tests::common::util::UCommand::succeeds
             at ./tests/common/util.rs:1782:9
   4: tests::test_uptime::test_uptime_with_file_containing_valid_boot_time_utmpx_record
             at ./tests/by-util/test_uptime.rs:114:5
   5: tests::test_uptime::test_uptime_with_file_containing_valid_boot_time_utmpx_record::{{closure}}
             at ./tests/by-util/test_uptime.rs:103:67
   6: core::ops::function::FnOnce::call_once
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/ops/function.rs:250:5
   7: core::ops::function::FnOnce::call_once
             at /rustc/129f3b9964af4d4a709d1383930ade12dfe7c081/library/core/src/ops/function.rs:250:5
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

[dezgeg]

Possibly this is due to the struct defined here being different on aarch64 (see the ifdef in C structure below):

coreutils/tests/by-util/test_uptime.rs

Line 154 in 15eaeae

pub struct Utmp {

struct utmp {
    short   ut_type;              /* Type of record */
    pid_t   ut_pid;               /* PID of login process */
    char    ut_line[UT_LINESIZE]; /* Device name of tty - "/dev/" */
    char    ut_id[4];             /* Terminal name suffix,
                                     or [inittab](https://linux.die.net/man/5/inittab)(5) ID */
    char    ut_user[UT_NAMESIZE]; /* Username */
    char    ut_host[UT_HOSTSIZE]; /* Hostname for remote login, or
                                     kernel version for run-level
                                     messages */
    struct  exit_status ut_exit;  /* Exit status of a process
                                     marked as DEAD_PROCESS; not
                                     used by Linux [init](https://linux.die.net/man/8/init)(8) */
    /* The ut_session and ut_tv fields must be the same size when
       compiled 32- and 64-bit.  This allows data files and shared
       memory to be shared between 32- and 64-bit applications. */
#if __WORDSIZE == 64 && defined __WORDSIZE_COMPAT32
    int32_t ut_session;           /* Session ID ([getsid](https://linux.die.net/man/2/getsid)(2)),
                                     used for windowing */
    struct {
        int32_t tv_sec;           /* Seconds */
        int32_t tv_usec;          /* Microseconds */
    } ut_tv;                      /* Time entry was made */
#else
     long   ut_session;           /* Session ID */
     struct timeval ut_tv;        /* Time entry was made */
#endif

   int32_t ut_addr_v6[4];        /* Internet address of remote
                                     host; IPv4 address uses
                                     just ut_addr_v6[0] */
    char __unused[20];            /* Reserved for future use */
};