capi/spec_helper.rb: use MAKE env
capi/spec_helper.rb: use MAKE env

* spec/rubyspec/optional/capi/spec_helper.rb (compile_extension):
  prefer MAKE environment variable to hardcoded name if set by
  parent make.

git-svn-id: ab86ecd26fe50a6a239cacb71380e346f71cee7d@59105 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

nobu/rubyspec,sgarciac/spec,nobu/rubyspec,eregon/rubyspec,sgarciac/spec,ruby/spec,nobu/rubyspec,eregon/rubyspec,ruby/rubyspec,ruby/rubyspec,eregon/rubyspec,ruby/spec,ruby/spec,sgarciac/spec