Fix incorrect file permissions of vmcore-dmesg-incomplete.txt
    
    Resolves: bz1955453
    Upstream: fedora
    Conflict: none
    
    commit ca05b754af74ab81525ff372f589ccfbc3ac81d9
    Author: Tao Liu <ltao@redhat.com>
    Date:   Mon May 10 22:10:26 2021 +0800
    
        Fix incorrect file permissions of vmcore-dmesg-incomplete.txt
    
        vmcore-dmesg-incomplete.txt is generated by shell redirection,
        which taking the default umask value. When dmesg collector exits
        with non-zero, the file will exist and anyone can have access to
        it.
    
        This patch fixed the issue by chmod the file, making it accessible
        only to its owner.
    
        Signed-off-by: Tao Liu <ltao@redhat.com>
        Acked-by: Kairui Song <kasong@redhat.com>
    
    Signed-off-by: Tao Liu <ltao@redhat.com>