m1n1.fw.isp: Fix message validity check

Signed-off-by: Asahi Lina <[email protected]>

Author: hoshinolina

proxyclient/m1n1/fw/isp/__init__.py

@@ -106,7 +106,7 @@ def __str__(self, max_count=3):
         return s
 
     def valid(self):  # rough check used for dumps
-        return (self.arg0 != 0x1) and (self.arg0 != 0x3) and (not (all(arg == 0x0 for arg in self.args)))
+        return not (self.arg0 & 0x1)
 
 class ISPChannel:
     """