Fixes command not found when calling check-grid with unknown arguments

[zoltanmeze]

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Description

Fixes command not found when calling check-grid with unknown arguments

Motivation and Context

It's causing issue only when check-grid is called with unknown arguments.
Function echoerr has been removed previously or was never defined.
Outputs message to stderr and exits with code 1 from while loop.

Currently it's failing with command not found error on base branch:

$ ./check-grid.sh --unknown_arg 8080
./check-grid.sh: line 22: echoerr: command not found

With echoerr fix:

$ ./check-grid.sh --unknown_arg 8080
Unknown argument: --unknown_arg

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• I have read the contributing document.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[diemol]

Thank you, @zoltanmeze!