create_gpu_instance: do not perform destroy_gpu_instance()

[Asd-g]

When performing destroy_gpu_instance(), g_instance.created is always 0.

[tencent-adm]

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 94.52%. Comparing base (6cdd711) to head (42de2cc).

Additional details and impacted files

@@           Coverage Diff            @@
##           master    #5437    +/-   ##
========================================
  Coverage   94.52%   94.52%            
========================================
  Files         780      780            
  Lines      243658   243552   -106     
========================================
- Hits       230314   230215    -99     
+ Misses      13344    13337     -7     

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[nihui]

Thanks for your contribution !