Modify README to keep consistency with Makefile

Use the name `validate` instead of `schema` for the
utility.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>

Author: hqhq

schema/Makefile

@@ -11,5 +11,6 @@ fmt:
 	for i in *.json ; do jq --indent 4 -M . "$${i}" > xx && cat xx > "$${i}" && rm xx ; done
 
 validate: validate.go
+	go get -d ./...
 	go build ./validate.go
 

schema/README.md

@@ -21,12 +21,18 @@ There is also included a simple utility for facilitating validation of a
 ```bash
 export GOPATH=`mktemp -d`
 go get -d ./...
-go build .
+go build ./validate.go
 rm -rf $GOPATH
 ```
 
+Or you can just use make command to create the utility:
+
+```bash
+make validate
+```
+
 Then use it like:
 
 ```bash
-./schema schema.json <yourpath>/config.json
+./validate schema.json <yourpath>/config.json
 ```