kdumpctl: Fix temporary directory location
    
    Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2215606
    Upstream: Fedora Rawhide
    Conflict: None
    
    commit dda81d72c2766167d48d3e505b95b2ca9b013039
    Author: Philipp Rudo <prudo@redhat.com>
    Date:   Mon Jun 19 14:31:48 2023 +0200
    
        kdumpctl: Fix temporary directory location
    
        The temporary directory is currently created under the current working
        directory. That alone isn't ideal but works most of the time. However,
        it will fail when the current working directory is not writable. So make
        sure the directory is created within TMPDIR.
    
        Fixes: ea00b7d ("kdumpctl: Move temp file in get_kernel_size to global temp dir")
        Signed-off-by: Philipp Rudo <prudo@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>