clang warnings

[polluks]

rim10-file.c:296:17: warning: comparison of integers of different signs: 'int' and 'unsigned long' [-Wsign-compare]
  for (i = 0; i < sizeof midas_rim10 / sizeof midas_rim10[0]; i++)
              ~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

tvpic.c:51:17: warning: comparison of integers of different signs: 'int' and 'unsigned int' [-Wsign-compare]
  for (y = 0; y < height; y++)
              ~ ^ ~~~~~~

constantinople.c:111:7: warning: variable 'start' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
  if (optind < argc)
      ^~~~~~~~~~~~~
constantinople.c:130:28: note: uninitialized use occurs here
  analyse_consta (&memory, start, end);
                           ^~~~~
constantinople.c:111:3: note: remove the 'if' if its condition is always true
  if (optind < argc)
  ^~~~~~~~~~~~~~~~~~
constantinople.c:93:12: note: initialize the variable 'start' to silence this warning
  int start, end;
           ^
            = 0
constantinople.c:116:7: warning: variable 'end' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
  if (optind < argc)
      ^~~~~~~~~~~~~
constantinople.c:130:35: note: uninitialized use occurs here
  analyse_consta (&memory, start, end);
                                  ^~~
constantinople.c:116:3: note: remove the 'if' if its condition is always true
  if (optind < argc)
  ^~~~~~~~~~~~~~~~~~
constantinople.c:93:17: note: initialize the variable 'end' to silence this warning
  int start, end;
                ^
                 = 0

dumper.c:141:37: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
    fprintf (f, "%s.%02ld", string, tv[0].tv_usec / 10000);
                    ~~~~~           ^~~~~~~~~~~~~~~~~~~~~
                    %02d
dumper.c:713:1: warning: unused function 'write_usr' [-Wunused-function]
write_usr (FILE *f)
^

acct.c:61:1: warning: unused function 'print_octal' [-Wunused-function]
print_octal (word_t word)
^

classify-tape.c:47:1: warning: unused function 'read_32bits_l' [-Wunused-function]
read_32bits_l (uint8_t *start)
^