Fix nodepool container failure

Nodepool container fails with error message:
whoami: extra operand ‘/dev/null’
Try 'whoami --help' for more information.

Change-Id: I7ef5b6527eb08d00b9b27e37b5d5b5dce69bb4ef

tools/uid_entrypoint.sh

@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-if ! whoami 2>&1 /dev/null; then
+if ! whoami 2>&1 >/dev/null; then
   if [ -w /etc/passwd ]; then
     echo "${USER_NAME:-default}:x:$(id -u):0:${USER_NAME:-default} user:${HOME}:/sbin/nologin" >> /etc/passwd
   fi