Fix stupid bugs

envbuffer.py

@@ -74,7 +74,7 @@ class EnvBuffer():
     return dict  
 
   def set_env(self, key, value):    
-    var[key] = value
+    self.var[key] = value
     
   def pack(self, bufsize, crc_prefix = None, encoding = None):
     crc_prefix = crc_prefix if crc_prefix is not None else self.crc_prefix

install_fw.py

@@ -610,7 +610,7 @@ if rootfs.cmd:
   if img_write:
     gw.run_cmd(rootfs.cmd, timeout = 60)
 
-if img_write:
+if not img_write:
   die('TEST is over')
 
 print("The firmware has been successfully flashed!")