treewide: use less phases if not necessary

This removes some skipping of e.g. fixupPhase and cleans up occurences
where this led to duplicating code

pkgs/tools/networking/tlspool/default.nix

@@ -23,11 +23,9 @@ stdenv.mkDerivation rec {
                   libkrb5 ldns libtool swig pkgs.pythonPackages.pip gnutls-kdh ]
                 ++ stdenv.lib.optional useSystemd systemd;
 
-  phases = [ "unpackPhase" "patchPhase" "postPatchPhase" "buildPhase" "installPhase" ]; 
-
   patches = [ ./fixing-rpath.patch ./configvar-fix.patch ];
 
-  postPatchPhase = ''
+  postPatch = ''
     substituteInPlace etc/tlspool.conf \
       --replace "dnssec_rootkey ../etc/root.key" "dnssec_rootkey $out/etc/root.key" \
       --replace "pkcs11_path /usr/local/lib/softhsm/libsofthsm2.so" "pkcs11_path ${softhsm}/lib/softhsm/libsofthsm2.so"