pahole: fix build (ZHF)

pkgs/development/tools/misc/pahole/default.nix

···
 
   postInstall = ''
     for p in $out/bin/*; do
-      rpath=`patchelf --print-rpath $p`:$out
-      patchelf --set-rpath $rpath $p
+      rpath=`patchelf --print-rpath $p || true`:$out
+      patchelf --set-rpath "$rpath" $p || true
     done
   '';