/kind cleanup

What needs cleanup:
[A clear and concise description of what needs to be cleaned up.]

Uses of field.NewPath() should use camel case as pointed out here: #4792 (comment)

Incorrect use of field.NewPath(): https://github.com/willie-yao/cluster-api-provider-azure/blob/37702d1053c3c3802a1f8c40b0d8f98e56eb41ae/api/v1beta1/azuremachine_webhook.go#L184

Correct use of field.NewPath(): https://github.com/willie-yao/cluster-api-provider-azure/blob/add-mp-ci-ipv6/api/v1beta1/azuremachine_webhook.go#L210

Describe the solution you'd like
[Description of how you would like the cleanup to be done.]
Fix all uses of field.NewPath() that don't follow camel case.

Anything else you would like to add:
[Miscellaneous information that will assist in solving the issue.]