drm/amdgpu/userq: cleanup amdgpu_userq_get/put where not needed

drm/amdgpu/userq: cleanup amdgpu_userq_get/put where not needed

amdgpu_userq_put/get are not needed in case we already holding
the userq_mutex and reference is valid already from queue create
time or from signal ioctl. These additional get/put could be a
potential reason for deadlock in case the ref count reaches zero
and destroy is called which again try to take the userq_mutex.

Due to the above change we avoid deadlock between suspend/restore
calling destroy queues trying to take userq_mutex again.

Cc: Prike Liang <Prike.Liang@amd.com>
Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>