libguestfs-find-requires: Be more specific about regexps matching library paths.
    
    In particular, don't match and convert filenames such as
    "/lib64/rtkaio/librt.so.1" but dump those out directly as
    dependencies (there is only one such file dependency in Rawhide).
    
    (cherry picked from commit 82faf4e03a43a5fb2a59d9b65dbd288bccde0b95)