tsm-client: fix symlink fixup

`tsm-client` binary distribution apparently no longer
contains any absolut `/usr/....` symlinks.
On the other hand, there are some relative `..../opt/....`
symlinks that haven't been fixed by the current build recipe.
This fact got uncovered by the new `no-broken-symlinks`
hook in aa1405b .

The commit at hand updates and shortens the symlink fixup
code such that it blanketly fixes all `...../opt/....` symlinks
by removing one `../` directory level for each target.

Author: Yarny0

pkgs/by-name/ts/tsm-client/package.nix

@@ -131,22 +131,11 @@ let
       runHook postInstall
     '';
 
-    # fix relative symlinks after `/usr` was moved up one level,
-    # fix absolute symlinks pointing to `/opt`
+    # fix symlinks pointing to `..../opt/....`
     preFixup = ''
-      for link in $out/lib{,64}/* $out/bin/*
+      for link in $(find $out -type l -lname '*../opt*')
       do
-        target=$(readlink "$link")
-        if [ "$(cut -b -6 <<< "$target")" != "../../" ]
-        then
-          echo "cannot fix this symlink: $link -> $target"
-          exit 1
-        fi
-        ln --symbolic --force --no-target-directory "$out/$(cut -b 7- <<< "$target")" "$link"
-      done
-      for link in $(find $out -type l -lname '/opt/*')
-      do
-        ln --symbolic --force --no-target-directory "$out$(readlink "$link")" "$link"
+        ln --symbolic --force --no-target-directory "$(readlink "$link" | sed 's|../opt|opt|')" "$link"
       done
     '';
   });