fix typos [ci skip]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56498 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

common.mk

@@ -613,7 +613,7 @@ yes-test-testframework: prog PHONY
 	$(Q)$(exec) $(RUNRUBY) "$(srcdir)/test/runner.rb" --ruby="$(RUNRUBY)" $(TESTOPTS) testunit minitest
 no-test-testframework: PHONY
 
-test-sample: test-basic # backword compatibility for mswin-build
+test-sample: test-basic # backward compatibility for mswin-build
 test: btest-ruby test-knownbug test-basic
 
 # $ make test-all TESTOPTS="--help" displays more detail

sample/test.rb

@@ -1,2 +1,2 @@
-# backword compatibility for chkbuild
+# backward compatibility for chkbuild
 require_relative '../basictest/test'