small build fix

netware/Makefile.am:
  use detected awk variant instead of using awk directly

netware/Makefile.am

@@ -54,7 +54,7 @@ DISTCLEANFILES =                $(BUILT_SOURCES)
 
 # Create the libmysql.imp from libmysql/libmysql.def
 libmysql.imp: $(top_srcdir)/libmysql/libmysql.def
-	awk 'BEGIN{x=0;} \
+	$(AWK) 'BEGIN{x=0;} \
              END{printf("\n");} \
              x==1 {printf(" %s",$$1); x++; next} \
              x>1 {printf(",\n %s", $$1); next} \