nvidia: also install useful nvidia-smi tool

pkgs/os-specific/linux/nvidia-x11/builder.sh

@@ -74,7 +74,7 @@ installPhase() {
         # Install the programs.
         mkdir -p $out/bin
 
-        for i in nvidia-settings nvidia-xconfig; do
+        for i in nvidia-settings nvidia-smi nvidia-xconfig; do
 	    cp $i $out/bin/$i
 	    patchelf --interpreter "$(cat $NIX_GCC/nix-support/dynamic-linker)" \
 	        --set-rpath $out/lib:$programPath:$glPath $out/bin/$i