execute verify-docker-install straight-up to use setopt

By executing `bash verify-docker-install`, the `bash -e` at the top of
the script is not honored. Should just execute the script straight-up
to use whatever `set` options are desired in the script.

Signed-off-by: Andrew Hsu <andrewhsu@docker.com>

Makefile

@@ -31,4 +31,4 @@ verify-install-%.log: needs_version needs_gitcommit
 		-v $(CURDIR):/v \
 		-w /v \
 		$(subst -,:,$*) \
-		bash verify-docker-install "$(EXPECTED_VERSION)" "$(EXPECTED_GITCOMMIT)" | tee $@
+		/v/verify-docker-install "$(EXPECTED_VERSION)" "$(EXPECTED_GITCOMMIT)" | tee $@