tools: Do not use os.EX_DATAERR due to unavailability on windows

Just return a plain exit code...

tools/dump2bin

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 import argparse
-import os, sys
+import sys
 
 from lib.dump import decode_dump
 
@@ -21,7 +21,7 @@ def main():
     # decode the dump data
     dump = decode_dump(args.dump)
     if dump is None:
-        return os.EX_DATAERR
+        return 1
 
     # output descriptors
     if args.info:

tools/elf_mem_map

@@ -4,7 +4,6 @@ import elftools.elf.elffile
 import elftools.dwarf.descriptions
 from collections import namedtuple
 from struct import unpack
-import os
 import re
 
 from lib.dump import decode_dump
@@ -374,7 +373,7 @@ def main():
         # fetch the memory data
         dump = decode_dump(args.dump)
         if dump is None:
-            return os.EX_DATAERR
+            return 1
 
         # strip padding, if present
         addr_start = dump.ranges[0][0]

tools/xfimg2dump

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 import argparse
 import struct
-import os, sys
+import sys
 
 from lib.dump import DUMP_MAGIC, DUMP_OFFSET, DUMP_SIZE
 
@@ -25,13 +25,13 @@ def main():
         data = fd.read(DUMP_SIZE)
     if len(data) != DUMP_SIZE:
         error('incorrect image size')
-        return os.EX_DATAERR
+        return 1
 
     # check for magic header
     magic, = struct.unpack('<L', data[:4])
     if magic != DUMP_MAGIC:
         error('invalid dump magic or no dump')
-        return os.EX_DATAERR
+        return 1
 
     # output D21 dump
     print('D21 - read crash dump', end='')