Always calculate/show cksum in dbgblock.py

Now that most scripts show relevant cksums, it makes sense for
dbgblock.py to just always show a cksum as well. It's not like this has
any noticable impact on the script's runtime.

Example:

  $ ./scripts/dbgblock.py disk -b4096 0
  block 0x0, size 4096, cksum e6e3ad25
  00000000: 01 00 00 00 80 03 00 08 6c 69 74 74 6c 65 66 73  ........littlefs
  00000010: 80 04 00 02 00 00 80 05 00 02 fa 01 80 09 00 04  ................
  ...

scripts/dbgblock.py

@@ -124,26 +124,25 @@ def main(disk, block=None, *,
                 else off[1] - off[0] if isinstance(off, tuple) and len(off) > 1
                 else block_size)
 
-        # print the header
-        print('block %s, size %d' % (
-            '0x%x.%x' % (block, off)
-                if off is not None
-                else '0x%x' % block,
-            size))
-
         # read the block
         f.seek((block * block_size) + (off or 0))
         data = f.read(size)
 
+        # calculate checksum
+        cksum = crc32c(data)
+
+        # print the header
+        print('block %s, size %d, cksum %08x' % (
+            '0x%x.%x' % (block, off)
+                if off is not None
+                else '0x%x' % block,
+            size,
+            cksum))
+
         # render the hex view
         for o, line in enumerate(xxd(data)):
             print('%08x: %s' % ((off or 0) + 16*o, line))
 
-        # render the checksum if requested
-        if cksum:
-            cksum = crc32c(data)
-            print('%8s: %08x' % ('crc32c', cksum))
-
 if __name__ == "__main__":
     import argparse
     import sys
@@ -178,10 +177,6 @@ if __name__ == "__main__":
             int(x, 0) if x.strip() else None
             for x in x.split(',')),
         help="Show this many bytes, may be a range.")
-    parser.add_argument(
-        '-c', '--cksum', '--crc32c',
-        action='store_true',
-        help="Calculate and show the crc32c of the data.")
     sys.exit(main(**{k: v
         for k, v in vars(parser.parse_intermixed_args()).items()
         if v is not None}))