Fix for Bug#33785 - myisamchk show warning message

myisamchk tool generates warnings when run on an myisam files (.MYI or .MYD)
This is because of the conversion of max_value for certain options in myisamchk 
from singed long to unsigned long

The max value for the options key_buffer_size, read_buffer_size, write_buffer
_size and sort_buffer_size is given as (long) ~0L which becomes -1  when casted
from signed long to longlong and then casted to ulonglong. When (ulonglong) -1 
is compared with maximal value for GET_ULONG data type, we adjust it to 
(ulonglong) ULONG_MAX and throw the warning.

Fixed by using the right max size.

Max values for the variables (from mysqld.cc)
----------------------------
1. key_buffer_size
   5.0: ULONG_MAX
   5.1: SIZE_T_MAX
   6.0: SIZE_T_MAX

2. read_buffer_size and write_buffer_size
   5.0: INT_MAX32
   5.1: INT_MAX32
   6.0: INT_MAX32

3. sort_buffer_size (aka myisam_sort_buffer_size)
   5.0: UINT_MAX32
   5.1: ULONG_MAX
   6.0: ULONG_MAX

Note: testcase not attached

myisam/myisamchk.c:
  Bug#33785 - myisamchk show warning message
      
  Fixed the Max value for key_buffer_size, read_buffer_size, write_buffer_size and
  sort_buffer_size options

myisam/myisamchk.c

@@ -295,7 +295,7 @@ static struct my_option my_long_options[] =
   { "key_buffer_size", OPT_KEY_BUFFER_SIZE, "",
     (gptr*) &check_param.use_buffers, (gptr*) &check_param.use_buffers, 0,
     GET_ULONG, REQUIRED_ARG, (long) USE_BUFFER_INIT, (long) MALLOC_OVERHEAD,
-    (long) ~0L, (long) MALLOC_OVERHEAD, (long) IO_SIZE, 0},
+    ULONG_MAX, (long) MALLOC_OVERHEAD, (long) IO_SIZE, 0},
   { "key_cache_block_size", OPT_KEY_CACHE_BLOCK_SIZE,  "",
     (gptr*) &opt_key_cache_block_size,
     (gptr*) &opt_key_cache_block_size, 0,
@@ -309,17 +309,17 @@ static struct my_option my_long_options[] =
     (gptr*) &check_param.read_buffer_length,
     (gptr*) &check_param.read_buffer_length, 0, GET_ULONG, REQUIRED_ARG,
     (long) READ_BUFFER_INIT, (long) MALLOC_OVERHEAD,
-    (long) ~0L, (long) MALLOC_OVERHEAD, (long) 1L, 0},
+    INT_MAX32, (long) MALLOC_OVERHEAD, (long) 1L, 0},
   { "write_buffer_size", OPT_WRITE_BUFFER_SIZE, "",
     (gptr*) &check_param.write_buffer_length,
     (gptr*) &check_param.write_buffer_length, 0, GET_ULONG, REQUIRED_ARG,
     (long) READ_BUFFER_INIT, (long) MALLOC_OVERHEAD,
-    (long) ~0L, (long) MALLOC_OVERHEAD, (long) 1L, 0},
+    INT_MAX32, (long) MALLOC_OVERHEAD, (long) 1L, 0},
   { "sort_buffer_size", OPT_SORT_BUFFER_SIZE, "",
     (gptr*) &check_param.sort_buffer_length,
     (gptr*) &check_param.sort_buffer_length, 0, GET_ULONG, REQUIRED_ARG,
     (long) SORT_BUFFER_INIT, (long) (MIN_SORT_BUFFER + MALLOC_OVERHEAD),
-    (long) ~0L, (long) MALLOC_OVERHEAD, (long) 1L, 0},
+    UINT_MAX32, (long) MALLOC_OVERHEAD, (long) 1L, 0},
   { "sort_key_blocks", OPT_SORT_KEY_BLOCKS, "",
     (gptr*) &check_param.sort_key_blocks,
     (gptr*) &check_param.sort_key_blocks, 0, GET_ULONG, REQUIRED_ARG,