[bug report] drm/amd/display: add set and get clock for testing purposes

[Dan Carpenter]

Hello Charlene Liu,

This is a semi-automatic email about new static checker warnings.

The patch 925f566cb7ae: "drm/amd/display: add set and get clock for
testing purposes" from Jun 27, 2019, leads to the following Smatch
complaint:

    drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_hw_sequencer.c:3230 dcn10_set_clock()
    error: we previously assumed 'dc->clk_mgr' could be null (see line 3226)

drivers/gpu/drm/amd/amdgpu/../display/dc/dcn10/dcn10_hw_sequencer.c
  3225	
  3226		if (dc->clk_mgr && dc->clk_mgr->funcs->get_clock)
                    ^^^^^^^^^^
Check for NULL

  3227					dc->clk_mgr->funcs->get_clock(dc->clk_mgr,
  3228							context, clock_type, &clock_cfg);

This is indented a bit too far.

  3229	
  3230		if (!dc->clk_mgr->funcs->get_clock)
                     ^^^^^^^^^^^^^
This will oops if ->clk_mgr is NULL

  3231			return DC_FAIL_UNSUPPORTED_1;
  3232	

regards,
dan carpenter