force mellanox role to fail if no hardware is present. I want this to be...

force mellanox role to fail if no hardware is present. I want this to be handled higher up where it is visible

roles/mellanox_drivers/tasks/main.yml

 ---
+
+- name: "Force this role to fail if no Mellanox hardware is present"
+  #Exclude the role via tags ans ansible-playbook --skip-tags mlx
+  shell: "lspci | grep Mellanox"
+
 - include_vars: mellanoxVars.yml
 
 - name: yum install dependencies
@@ -39,8 +44,8 @@
   changed_when: False
 
 - name: set install due to drivers not installed
-  set_fact: 
-    install_now: true 
+  set_fact:
+    install_now: true
     reboot_now: true
   when: drivers_installed.failed
 
@@ -60,7 +65,7 @@
   debug: var=install_now
 
 - name: copy driver source
-  unarchive: copy=no src="http://consistency0/src/{{ MELLANOX_DRIVER_SRC }}.tgz" dest=/tmp 
+  unarchive: copy=no src="http://consistency0/src/{{ MELLANOX_DRIVER_SRC }}.tgz" dest=/tmp
   become: true
   become_user: root
   when: install_now