scripts: ensure signrom treats data as bytes

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <20180116134217.8725-10-berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

scripts/signrom.py

@@ -18,7 +18,7 @@
 fout = open(sys.argv[2], 'wb')
 
 magic = fin.read(2)
-if magic != '\x55\xaa':
+if magic != b'\x55\xaa':
     sys.exit("%s: option ROM does not begin with magic 55 aa" % sys.argv[1])
 
 size_byte = ord(fin.read(1))
@@ -33,7 +33,7 @@
     # Add padding if necessary, rounding the whole input to a multiple of
     # 512 bytes according to the third byte of the input.
     # size-1 because a final byte is added below to store the checksum.
-    data = data.ljust(size-1, '\0')
+    data = data.ljust(size-1, b'\0')
 else:
     if ord(data[-1:]) != 0:
         sys.stderr.write('WARNING: ROM includes nonzero checksum\n')