dabuild: per @tcely, `mkdir -p` then test for success

dabuild.in

@@ -43,11 +43,11 @@ fi
 ## check $DABUILD_PACKAGES is a writable directory
 ABUILD_PACKAGES=${DABUILD_PACKAGES:-${PWD%/aports*}/packages/${ABUILD_VERSION}}
 
+mkdir -p $ABUILD_PACKAGES
 if [ ! \( -d "$ABUILD_PACKAGES" -a -w "$ABUILD_PACKAGES" \) ]; then
-  mkdir -p $ABUILD_PACKAGES \
-    || die "Error: invalid packages directory specified!" \
-           "ABUILD_PACKAGES = '$ABUILD_PACKAGES'" \
-           "DABUILD_PACKAGES = '$DABUILD_PACKAGES'"
+  die "Error: invalid or unwritable packages directory specified!" \
+      "ABUILD_PACKAGES = '$ABUILD_PACKAGES'" \
+      "DABUILD_PACKAGES = '$DABUILD_PACKAGES'"
 fi
 
 ## setup volumes; use named volumes as cache if desired