cfgfile: fix read of empty file

If the file to be read by the cfgfile is empty, i.e. no configuration
data, but possibly comments present, the cfgfile should not mark the
last processed section (curr_section) as having N entries, since there
is no last processed section.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>

lib/librte_cfgfile/rte_cfgfile.c

@@ -225,8 +225,10 @@ rte_cfgfile_load(const char *filename, int flags)
 	}
 	fclose(f);
 	cfg->flags = flags;
-	cfg->sections[curr_section]->num_entries = curr_entry + 1;
 	cfg->num_sections = curr_section + 1;
+	/* curr_section will still be -1 if we have an empty file */
+	if (curr_section >= 0)
+		cfg->sections[curr_section]->num_entries = curr_entry + 1;
 	return cfg;
 
 error1: