fix singleton sed

pkg-deps.sh

@@ -43,7 +43,7 @@ GHC_PKGS="array base-4 base-3 bin-package-db $(ghc-pkg --simple-output list byte
 for i in $GHC_PKGS; do sed -i -e /$i/d pkgs.dot; done
 
 # remove singletons
-sed -i -e /^"[^ ]*"$/d pkgs.dot
+sed -i -e '/^"[^ ]*"$/d' pkgs.dot
 
 which tred &>/dev/null || { echo "graphviz is needed to generate graph" ; exit 1 ; }
 cat pkgs.dot | tred | dot -Nfontsize=8 -Tsvg >pkgs.svg