Makefile: Rename the 'vm-test' target as 'vm-help'

We already have 'make check-help', use the 'make vm-help' form
to display helps about VM testing. Keep the old target to not
bother old customs.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20190531064341.29730-1-philmd@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
diff --git a/Makefile b/Makefile
index 45cc2f4..c63de4e 100644
--- a/Makefile
+++ b/Makefile
@@ -13,7 +13,7 @@
 UNCHECKED_GOALS := %clean TAGS cscope ctags dist \
     html info pdf txt \
     help check-help print-% \
-    docker docker-% vm-test vm-build-%
+    docker docker-% vm-help vm-test vm-build-%
 
 print-%:
 	@echo '$*=$($*)'
@@ -1153,7 +1153,7 @@
 	@echo  'Test targets:'
 	@echo  '  check           - Run all tests (check-help for details)'
 	@echo  '  docker          - Help about targets running tests inside Docker containers'
-	@echo  '  vm-test         - Help about targets running tests inside VM'
+	@echo  '  vm-help         - Help about targets running tests inside VM'
 	@echo  ''
 	@echo  'Documentation targets:'
 	@echo  '  html info pdf txt'