- fix typo

Makefile.help

@@ -8,7 +8,7 @@
 help:
 	@echo 'Cleaning:'
 	@echo '  clean			- delete temporary object files'
-	@echo '  realclean		- delete temporary object file, including dependencies'
+	@echo '  realclean		- delete temporary object files, including dependencies'
 	@echo '  distclean		- delete all non-source files (including .config)'
 	@echo
 	@echo 'Build:'