thermal: change result string to standard for check_valid_temp

changing as required by lava

Signed-off-by: Sanjay Singh Rawat <sanjay.rawat@linaro.org>
diff --git a/include/thermal_functions.sh b/include/thermal_functions.sh
index 0c836c5..f3c4783 100644
--- a/include/thermal_functions.sh
+++ b/include/thermal_functions.sh
@@ -43,11 +43,11 @@
     log_begin "checking $descr"
 
     if [ $temp_val -gt 0 ]; then
-        log_end "pass"
+        log_end "Ok"
         return 0
     fi
 
-    log_end "fail"
+    log_end "Err"
 
     return 1
 }