readelf: memory leaks in process_dynamic_section

readelf: memory leaks in process_dynamic_section

This fixes some code that assumed only one PT_LOAD would contain
DT_SYMTAB.  Which is normally the case, but fuzzers thoroughly mess
with object files.

	* readelf.c (get_num_dynamic_syms): Check for nbuckets and nchains
	non-zero.
	(process_dynamic_section): Call get_num_dynamic_syms once rather
	than in segment loop.  Break out of segment loop on a successful
	load of dynamic symbols.  Formatting.
	(process_object): Return error status from process_dynamic_section.