Rename mrbgems/mruby-inline-struct with mrbgems/mruby-test-inline-struct

This gem contains only tests.

mrbgems/mruby-test-inline-struct/mrbgem.rake

@@ -1,4 +1,4 @@
-MRuby::Gem::Specification.new('mruby-inline-struct') do |spec|
+MRuby::Gem::Specification.new('mruby-test-inline-struct') do |spec|
   spec.license = 'MIT'
   spec.author  = 'mruby developers'
   spec.summary = 'inline structure'

mrbgems/mruby-test-inline-struct/test/inline.c

@@ -69,7 +69,7 @@ istruct_test_mutate(mrb_state *mrb, mrb_value self)
   return mrb_nil_value();
 }
 
-void mrb_mruby_inline_struct_gem_test(mrb_state *mrb)
+void mrb_mruby_test_inline_struct_gem_test(mrb_state *mrb)
 {
   struct RClass *cls;