docker.Makefile: fix phony targets (pytorch#82941)

### Description
Updated phony targets in `docker.Makefile` to refer to the `make` target called directly after `.PHONY` declarations. This was probably the author's intention.

### Issue
None - this is a simple fix.

### Testing
* Ran `make -f docker.Makefile devel-push`
* Ran `make -f docker.Makefile runtime-push`

Pull Request resolved: pytorch#82941
Approved by: https://github.com/kit1980

docker.Makefile

@@ -48,7 +48,7 @@ devel-image: DOCKER_TAG := $(PYTORCH_VERSION)-devel
 devel-image:
 	$(DOCKER_BUILD)
 
-.PHONY: devel-image
+.PHONY: devel-push
 devel-push: BASE_IMAGE := $(BASE_DEVEL)
 devel-push: DOCKER_TAG := $(PYTORCH_VERSION)-devel
 devel-push:
@@ -61,7 +61,7 @@ runtime-image:
 	$(DOCKER_BUILD)
 	docker tag $(DOCKER_FULL_NAME):$(DOCKER_TAG) $(DOCKER_FULL_NAME):latest
 
-.PHONY: runtime-image
+.PHONY: runtime-push
 runtime-push: BASE_IMAGE := $(BASE_RUNTIME)
 runtime-push: DOCKER_TAG := $(PYTORCH_VERSION)-runtime
 runtime-push: