HADOOP-14815. s3guard shell usage calls function incorrectly.

Contributed by Allen Wittenauer

hadoop-tools/hadoop-aws/src/main/shellprofile.d/hadoop-s3guard.sh

@@ -18,7 +18,7 @@
 if ! declare -f hadoop_subcommand_s3guard >/dev/null 2>/dev/null; then
 
   if [[ "${HADOOP_SHELL_EXECNAME}" = hadoop ]]; then
-    hadoop_add_subcommand "s3guard" "manage metadata on S3"
+    hadoop_add_subcommand "s3guard" client "manage metadata on S3"
   fi
 
   # this can't be indented otherwise shelldocs won't get it