perf hist: In init, ensure mem_info is put on error paths

Rather than exit the internal map_symbols directly, put the mem-info
that does this and also lowers the reference count on the mem-info
itself otherwise the mem-info is being leaked.

Fixes: 56e144fe98260a0f ("perf mem_info: Add and use map_symbol__exit and addr_map_symbol__exit")
Signed-off-by: Ian Rogers <[e-mail]>
Reviewed-by: Arnaldo Carvalho de Melo <[e-mail]>
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/util/hist.c

···
 		map_symbol__exit(&he->branch_info->to.ms);
 		zfree(&he->branch_info);
 	}
-	if (he->mem_info) {
-		map_symbol__exit(&mem_info__iaddr(he->mem_info)->ms);
-		map_symbol__exit(&mem_info__daddr(he->mem_info)->ms);
-	}
+	if (he->mem_info)
+		mem_info__zput(he->mem_info);
 err:
 	map_symbol__exit(&he->ms);
 	zfree(&he->stat_acc);