* common.mk: nmake doesn't recognize ${} form. use $() instead.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48025 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

common.mk

@@ -1098,7 +1098,7 @@ update-unicode: PHONY
 lib/unicode_normalize/tables.rb: tool/unicode_norm_gen.rb \
 enc/unicode/data/UnicodeData.txt \
 enc/unicode/data/CompositionExclusions.txt
-	${BASERUBY} -C "$(srcdir)/tool tool/unicode_norm_gen.rb
+	$(BASERUBY) -C "$(srcdir)/tool tool/unicode_norm_gen.rb
 
 info: info-program info-libruby_a info-libruby_so info-arch
 info-program: PHONY