scripts/bloat-o-meter: switch argument parsing to using argparse

This will facilitate further extension to the arguments the script takes. 
As an added benefit it also produces saner usage output, where mutual
exclusivity of the c|d|t parameters is clearly visible:

./scripts/bloat-o-meter  -h
usage: bloat-o-meter [-h] [-c | -d | -t] file1 file2

Simple script used to compare the symbol sizes of 2 object files

positional arguments:
  file1       First file to compare
  file2       Second file to compare

optional arguments:
  -h, --help  show this help message and exit
  -c          categorize output based on symbol type
  -d          Show delta of Data Section
  -t          Show delta of text Section

Link: https://lkml.kernel.org/r/20220701113513.1938008-1-nborisov@suse.com


Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>