drm/amdkfd: fix freeing an unset pointer

clang static analysis reports this problem
kfd_chardev.c:2092:2: warning: 1st function call argument
  is an uninitialized value
        kvfree(bo_privs);
        ^~~~~~~~~~~~~~~~

When bo_buckets alloc fails, it jumps to an error handler
that frees the yet to be allocated bo_privs.  Because
bo_buckets is the first error, return directly.

Fixes: 5ccbb05 ("drm/amdkfd: CRIU Implement KFD checkpoint ioctl")
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdkfd/kfd_chardev.c

@@ -1708,10 +1708,8 @@ static int criu_checkpoint_bos(struct kfd_process *p,
 	void *mem;
 
 	bo_buckets = kvzalloc(num_bos * sizeof(*bo_buckets), GFP_KERNEL);
-	if (!bo_buckets) {
-		ret = -ENOMEM;
-		goto exit;
-	}
+	if (!bo_buckets)
+		return -ENOMEM;
 
 	bo_privs = kvzalloc(num_bos * sizeof(*bo_privs), GFP_KERNEL);
 	if (!bo_privs) {