drm/amdgpu: prevent BO_HANDLES error from being overwritten

Before this patch, if multiple BO_HANDLES chunks were submitted,
the error -EINVAL would be correctly set but could be overwritten
by the return value from amdgpu_cs_p1_bo_handles(). This patch
ensures that if there are multiple BO_HANDLES, we stop.

Fixes: fec5f8e8 ("drm/amdgpu: disallow multiple BO_HANDLES chunks in one submit")
Signed-off-by: Mohammed Anees <pvmohammedanees2003@gmail.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>