update_engine: Remove EOL_DATE missing warning

The warning log is logged everytime status is asked for to update_engine
and prefs for EOL date is missing. This log can be removed.

BUG=none
TEST=unittests

Change-Id: Ie9e5494a46b7331d605e690e15d4d0bf936bde9b
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/2037641
Tested-by: Jae Hoon Kim <kimjae@chromium.org>
Auto-Submit: Jae Hoon Kim <kimjae@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
Commit-Queue: Jae Hoon Kim <kimjae@chromium.org>
diff --git a/omaha_utils.cc b/omaha_utils.cc
index 1ef8049..c7f9921 100644
--- a/omaha_utils.cc
+++ b/omaha_utils.cc
@@ -29,10 +29,8 @@
 
 EolDate StringToEolDate(const std::string& eol_date) {
   EolDate date = kEolDateInvalid;
-  if (!base::StringToInt64(eol_date, &date)) {
-    LOG(WARNING) << "Invalid EOL date attribute: " << eol_date;
+  if (!base::StringToInt64(eol_date, &date))
     return kEolDateInvalid;
-  }
   return date;
 }