Simplify bash remediation

The group must exist and must be empty. Reduced the number of commands
to achieve these goals.

linux_os/guide/system/accounts/accounts-restrictions/root_logins/ensure_pam_wheel_group_empty/bash/shared.sh

@@ -7,9 +7,4 @@ if ! grep -q "^${var_pam_wheel_group_for_su}:[^:]*:[^:]*:[^:]*" /etc/group; then
 fi
 
 # group must be empty
-grp_memb=$(groupmems -g ${var_pam_wheel_group_for_su} -l)
-if [ -n "${grp_memb}" ]; then
-    for memb in ${grp_memb}; do
-        deluser ${memb} ${var_pam_wheel_group_for_su}
-    done
-fi
+groupmems -g ${var_pam_wheel_group_for_su} -p