libffi.mk.tmpl: fix STATICLIB

* ext/fiddle/win32/libffi.mk.tmpl (STATICLIB): fix static library
  name.  [ruby-core:67128]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49009 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2014-12-26

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49010 b2dd03c8-39d4-4d8f-98ff-823fe69b080e