use DCS_TYPE_COUNT rather than a literal integer

src/gen_dcs_classifier.pl

@@ -964,7 +964,7 @@ const char *dcs_checksum = DCS_CHECKSUM;
 EOF
 
 _VCL (F_CLASSIFIER_C, VCL_TOP, 
-      'const char * const dcs_type['.scalar(keys %typeenum2nbtype)."] = {\n\t".
+      "const char * const dcs_type[DCS_TYPE_COUNT] = {\n\t".
       join(",\n\t",
 	   map { '['.$_.'] = "'.c_escape($typeenum2nbtype{$_}).'"' }
 	   sort keys %typeenum2nbtype).