drivers/elog: remove unnecessary check in elog_shrink()

There was a check against the next event offset against
the shrink size in elog_shrink(). However, all calls
to elog_shrink() were conditionalized on the next
event offset exceeding the full threshold. The shrink
size is set to the minimum of the full threshold and
a percentage of the elog region size. Therefore, it's
impossible for the next event offset to be less than
the shrink size because full threshold is always greater
than or equal to the shrink size.

BUG=chrome-os-partner:55932

Change-Id: Ie6ff106f1c53c15aa36a82223a235a7ac97fd8c7
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/16093
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/drivers/elog/elog.c

@@ -352,9 +352,6 @@ static int elog_shrink(void)
 
 	elog_debug("elog_shrink()\n");
 
-	if (next_event_offset < shrink_size)
-		return 0;
-
 	while (1) {
 		/* Next event has exceeded constraints */
 		if (offset > shrink_size)