net: ena: fix PHC cleanup on probe failure

ena_probe() initializes the PHC as part of ena_device_init(), but the
probe failure path does not destroy it before freeing the PHC private
data.

The normal removal path calls ena_phc_destroy() through
ena_destroy_device() before ena_phc_free(). However, if probe fails
after ena_device_init() succeeds, the error path reaches ena_phc_free()
without unregistering the PTP clock or destroying the device PHC
resources.

Call ena_phc_destroy() in the probe error path before freeing the PHC
private data.

This issue was found by manual code inspection.

Cc: stable@vger.kernel.org tags and describe this as a consistency cleanup
Fixes: e0ea34158ee8 ("net: ena: Add PHC support in the ENA driver")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Cc: stable
Link: https://patch.msgid.link/20260921154202.471662-2-lgs201920130244@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>