simg_dump.py: fix error for CHUNK_TYPE_FILL

In python3, division of two integers produces a float,
which cannot be used to multiply a bytes sequence.

Using // to produce an integer quotient.

Bug: 245257511
Test: ./system/core/libsparse/simg_dump.py -sv path/to/image
Change-Id: Ibe95056409ac3676a68f5e7693331ca4a66e9fb7

libsparse/simg_dump.py

diff --git a/libsparse/simg_dump.py b/libsparse/simg_dump.py
index 8811a52..47537ca 100755
--- a/libsparse/simg_dump.py
+++ b/libsparse/simg_dump.py
@@ -158,7 +158,7 @@
           curtype = format("Fill with 0x%08X" % (fill))
           if showhash:
             h = hashlib.sha1()
-            data = fill_bin * (blk_sz / 4);
+            data = fill_bin * (blk_sz // 4);
             for block in range(chunk_sz):
               h.update(data)
             curhash = h.hexdigest()