This patch fixes the following kernel warning seen during
driver load by correctly initializing the p2plink attr before
creating the sysfs file:

[  +0.002865] ------------[ cut here ]------------
[  +0.002327] kobject: '(null)' (0000000056260cfb): is not initialized, yet kobject_put() is being called.
[  +0.004780] WARNING: CPU: 32 PID: 1006 at lib/kobject.c:718 kobject_put+0xaa/0x1c0
[  +0.001361] Call Trace:
[  +0.001234]  <TASK>
[  +0.001067]  kfd_remove_sysfs_node_entry+0x24a/0x2d0 [amdgpu]
[  +0.003147]  kfd_topology_update_sysfs+0x3d/0x750 [amdgpu]
[  +0.002890]  kfd_topology_add_device+0xbd7/0xc70 [amdgpu]
[  +0.002844]  ? lock_release+0x13c/0x2e0
[  +0.001936]  ? smu_cmn_send_smc_msg_with_param+0x1e8/0x2d0 [amdgpu]
[  +0.003313]  ? amdgpu_dpm_get_mclk+0x54/0x60 [amdgpu]
[  +0.002703]  kgd2kfd_device_init.cold+0x39f/0x4ed [amdgpu]
[  +0.002930]  amdgpu_amdkfd_device_init+0x13d/0x1f0 [amdgpu]
[  +0.002944]  amdgpu_device_init.cold+0x1464/0x17b4 [amdgpu]
[  +0.002970]  ? pci_bus_read_config_word+0x43/0x80
[  +0.002380]  amdgpu_driver_load_kms+0x15/0x100 [amdgpu]
[  +0.002744]  amdgpu_pci_probe+0x147/0x370 [amdgpu]
[  +0.002522]  local_pci_probe+0x40/0x80
[  +0.001896]  work_for_cpu_fn+0x10/0x20
[  +0.001892]  process_one_work+0x26e/0x5a0
[  +0.002029]  worker_thread+0x1fd/0x3e0
[  +0.001890]  ? process_one_work+0x5a0/0x5a0
[  +0.002115]  kthread+0xea/0x110
[  +0.001618]  ? kthread_complete_and_exit+0x20/0x20
[  +0.002422]  ret_from_fork+0x1f/0x30
[  +0.001808]  </TASK>
[  +0.001103] irq event stamp: 59837
[  +0.001718] hardirqs last  enabled at (59849): [<ffffffffb30fab12>] __up_console_sem+0x52/0x60
[  +0.004414] hardirqs last disabled at (59860): [<ffffffffb30faaf7>] __up_console_sem+0x37/0x60
[  +0.004414] softirqs last  enabled at (59654): [<ffffffffb307d9c7>] irq_exit_rcu+0xd7/0x130
[  +0.004205] softirqs last disabled at (59649): [<ffffffffb307d9c7>] irq_exit_rcu+0xd7/0x130
[  +0.004203] ---[ end trace 0000000000000000 ]---

Fixes: 0f28cca8 ("drm/amdkfd: Extend KFD device topology to surface peer-to-peer links")
Signed-off-by: Mukul Joshi <mukul.joshi@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org