fix typo in pid file read/write error logs.

[zhouyixiang]

No description provided.

[megaeasex]

[TASK:easegress-pr-test FAILED]megaease/easegress Pull Request 286 Deploy Test failed

[codecov-commenter]

Codecov Report

Merging #286 (1bda474) into main (19d9ecd) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #286   +/-   ##
=======================================
  Coverage   80.18%   80.18%           
=======================================
  Files          44       44           
  Lines        4865     4865           
=======================================
  Hits         3901     3901           
  Misses        742      742           
  Partials      222      222           

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[megaeasex]

[TASK:easegress-pr-test SUCCESS]megaease/easegress Pull Request 286 Deploy Test Success