Add patch to work around FTBFS on rawhide
    
    This commit adds a temporary workaround for failing builds with the new
    4.18-rcX kernel on rawhide. The issue will likely be fixed in the kernel
    before the final 4.18 release. The workaround can be removed then.
    
    Upstream issue: https://github.com/smuellerDD/libkcapi/issues/59