dmaengine: ptdma: Remove dead code from pt_dmaengine_register()

dmaengine: ptdma: Remove dead code from pt_dmaengine_register()

devm_kasprintf() is used to allocate and format a string and the
returned pointer is assigned to 'cmd_cache_name'. However, the variable
'cmd_cache_name' is not effectively used.

Remove the dead code.

Signed-off-by: Eder Zulian <ezulian@redhat.com>
Reviewed-by: Nathan Lynch <nathan.lynch@amd.com>
Acked-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
Link: https://lore.kernel.org/r/20250411165451.240830-1-ezulian@redhat.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>