drm/amdgpu: clean up the amdgpu_cs_parser_bos

In low memory conditions, kmalloc can fail. In such conditions
unlock the mutex for a clean exit.

We do not need to amdgpu_bo_list_put as it's been handled in the
amdgpu_cs_parser_fini.

Fixes: 737da53 ("drm/amdgpu: update the functions to use amdgpu version of hmm")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202602030017.7E0xShmH-lkp@intel.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>

Author: amd-sukhatri

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

@@ -892,8 +892,10 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 		struct amdgpu_bo *bo = e->bo;
 
 		e->range = amdgpu_hmm_range_alloc(NULL);
-		if (unlikely(!e->range))
-			return -ENOMEM;
+		if (unlikely(!e->range)) {
+			r = -ENOMEM;
+			goto out_free_user_pages;
+		}
 
 		r = amdgpu_ttm_tt_get_user_pages(bo, e->range);
 		if (r)