Use the correct command to get architecture
    
    Related: bz2060319
    Upstream: Fedora
    Conflict: None
    
    commit 12e6cd2b76a10bb6b52c0cc28ad0e8c8f57a319a
    Author: Coiby Xu <coxu@redhat.com>
    Date:   Mon Feb 20 17:33:08 2023 +0800
    
        Use the correct command to get architecture
    
        `uname -r` was used by mistake. As a result, kexec-tools failed to
        update crashkernel=auto during in-place upgrade from RHEL8 to RHEL9.
    
        `uname -m` should be used to get architecture instead.
    
        Fixes: 5951b5e2 ("Don't try to update crashkernel when bootloader is not installed")
    
        Signed-off-by: Coiby Xu <coxu@redhat.com>
        Reviewed-by: Lichen Liu <lichliu@redhat.com>
    
    Signed-off-by: Coiby Xu <coxu@redhat.com>