drm/amdgpu: Fix missing unwind in amdgpu_ib_schedule() error path

drm/amdgpu: Fix missing unwind in amdgpu_ib_schedule() error path

amdgpu_ib_schedule() returns early after calling amdgpu_ring_undo().
This skips the common free_fence cleanup path.  Other error paths were
already changed to use goto free_fence, but this one was missed.

Change the early return to goto free_fence so all error paths clean up
the same way.

Fixes the below:
drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c:232 amdgpu_ib_schedule()
warn: missing unwind goto?

drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c
    124 int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned int num_ibs,
    125                        struct amdgpu_ib *ibs, struct amdgpu_job *job,
    126                        struct dma_fence **f)
    127 {

    ...

    224
    225         if (ring->funcs->insert_start)
    226                 ring->funcs->insert_start(ring);
    227
    228         if (job) {
    229                 r = amdgpu_vm_flush(ring, job, need_pipe_sync);
    230                 if (r) {
    231                         amdgpu_ring_undo(ring);
--> 232                         return r;

	The patch changed the other error paths to goto free_fence but
	this one was accidentally skipped.

    233                 }
    234         }
    235
    236         amdgpu_ring_ib_begin(ring);

    ...

    338
    339 free_fence:
    340         if (!job)
    341                 kfree(af);
    342         return r;
    343 }

Fixes: f903b85ed0f1 ("drm/amdgpu: fix possible fence leaks from job structure")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>