* [TD-3197]<fix>: taosdemo and taosdump coverity scan issues.

* exit if read sample file failed.

* fix converity scan issue.

* fix coverity scan issue.

* fix coverity scan memory leak.

* fix resource leak reported by coverity scan.

* fix taosdemo coverity scan issue.

* fix tcsetattr and getchar return value determination bug.

* fix coverity scan issue.

* fix two more coverity scan issues.

* fix stmt batch coverity scan issue.

* change to portable format.
Co-authored-by: NShuduo Sang <sdsang@taosdata.com>