stdenv/setup.sh: fix previous change...

for the case that there is no makefile. CC #1354

pkgs/stdenv/generic/setup.sh

@@ -109,9 +109,6 @@ runHook preHook
 # Check that the pre-hook initialised SHELL.
 if [ -z "$SHELL" ]; then echo "SHELL not set"; exit 1; fi
 
-# see https://github.com/NixOS/nixpkgs/pull/1354#issuecomment-31260409
-makeFlags="${makeFlags} SHELL=${SHELL}"
-
 # Hack: run gcc's setup hook.
 envHooks=()
 crossEnvHooks=()
@@ -617,6 +614,9 @@ buildPhase() {
         return
     fi
 
+    # see https://github.com/NixOS/nixpkgs/pull/1354#issuecomment-31260409
+    makeFlags="${makeFlags} SHELL=${SHELL}"
+
     echo "make flags: $makeFlags ${makeFlagsArray[@]} $buildFlags ${buildFlagsArray[@]}"
     make ${makefile:+-f $makefile} \
         ${enableParallelBuilding:+-j${NIX_BUILD_CORES} -l${NIX_BUILD_CORES}} \