drm/amdgpu: Fix complex macros error

Fixes the below:

ERROR: Macros with complex values should be enclosed in parentheses

WARNING: macros should not use a trailing semicolon
+#define amdgpu_inc_vram_lost(adev) atomic_inc(&((adev)->vram_lost_counter));

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>