drm/amd/amdgpu: Fix error do not initialise globals to 0

Global variables do not need to be initialized to 0 and checkpatch
flags this error in drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c:

ERROR: do not initialise globals to 0
+int amdgpu_no_queue_eviction_on_vm_fault = 0;

Fix this checkpatch error.

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Hamza Mahfooz <Hamza.Mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>