trivial: Fix misspelling of "Celsius".

A few comments say "Celcius"; this fixes them. No code changes.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 7c27c8b..056ac77 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -295,7 +295,7 @@
 static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
 
 
-/* Sysfs conventions report temperatures in millidegrees Celcius.
+/* Sysfs conventions report temperatures in millidegrees Celsius.
  * ADS7846 could use the low-accuracy two-sample scheme, but can't do the high
  * accuracy scheme without calibration data.  For now we won't try either;
  * userspace sees raw sensor values, and must scale/calibrate appropriately.