Fix code scanning alert - Time-of-check time-of-use filesystem race condition

[Daniel Wagner]

nvme-cli/plugins/micron/micron-nvme.c

Line 332 in 79abafe

 rmdir(strMainDirName); 

Often it is necessary to check the state of a file before using it. These checks usually take a file name to be checked, and if the check returns positively, then the file is opened or otherwise operated upon.

Tracking issue for:

• https://github.com/linux-nvme/nvme-cli/security/code-scanning/4

[ikegami-t]

This issue also can be closed.