PR31096, nm shows 32bit addresses as 64bit addresses

Prior to commit 0e3c1eeb nm output depended on the host unsigned
long when printing "negative" symbol values for 32-bit targets.
Commit 0e3c1eeb made the output match that seen with a 64-bit host
unsigned long.  The fact that nm output changed depending on host is
of course a bug, but it is reasonable to expect 32-bit target output
is only 32 bits.  So this patch makes 32-bit target output the same as
it was on 32-bit hosts prior to 0e3c1eeb.

	PR 31096
	* nm.c (print_format_string): Make it a static buffer.
	(get_print_format): Merge into..
	(set_print_format): ..this, renamed from set_print_width.  When
	print_width is 32, set up print_format_string for an int32_t
	value.  Don't malloc print_format_string.  Adjust calls.
	(print_value): Correct printing of 32-bit values.