The code testing if a temperature should be emulated or not is
not obvious. Add a comment explaining why this test is done.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
  drivers/thermal/thermal_core.c | 5 +++++
  1 file changed, 5 insertions(+)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 3e0fe55..e204deb 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c

@@ -435,6 +435,11 @@ int thermal_zone_get_temp(struct thermal_zone_device *tz, int *temp)
  			}
  		}

+		/*
+		 * Only allow emulating a temperature when the real temperature
+		 * is below the critical temperature so that the emulation code
+		 * cannot hide critical conditions.
+		 */
  		if (!ret && *temp < crit_temp)
  			*temp = tz->emul_temperature;
  	}