Don't clear screen twice at startup

* Combined init_global_vars and add_devs output

.bin/Scripts/functions/hw_diags.py

@@ -166,7 +166,10 @@ class State():
       'badblocks':        {'Enabled': False, 'Order': 3},
       'I/O Benchmark':    {'Enabled': False, 'Order': 4},
     }
-    self.add_devs()
+    try_and_print(
+      message='Scanning devices...',
+      function=self.add_devs,
+      cs='Done')
 
   def add_devs(self):
     """Add all block devices listed by lsblk."""

.bin/Scripts/hw-diags-menu

@@ -13,9 +13,6 @@ init_global_vars()
 
 if __name__ == '__main__':
     try:
-        # Prep
-        clear_screen()
-
         # Show menu
         state = State()
         menu_diags(state, sys.argv)