kdumpctl: Move get_kernel_size to kdumpctl
    
    Resolves: bz2169720
    Upstream: src.fedoraproject.org/rpms/kexec-tools.git
    Conflicts: None
    
    commit 81d89c885f2c07d30738f2a942c23f7b81e60cd0
    Author: Philipp Rudo <prudo@redhat.com>
    Date:   Fri May 5 17:14:40 2023 +0200
    
        kdumpctl: Move get_kernel_size to kdumpctl
    
        The function is only used in do_estimate. Move it to kdumpctl to
        prevent confusion.
    
        Signed-off-by: Philipp Rudo <prudo@redhat.com>
        Reviewed-by: Pingfan Liu <piliu@redhat.com>
        Reviewed-by: Coiby Xu <coxu@redhat.com>
    
    Signed-off-by: Philipp Rudo <prudo@redhat.com>
    Signed-off-by: Tao Liu <ltao@redhat.com>