msm: kgsl: Reimplement the timestamp comparison function

Make timestamp_cmp return -1, 0 or 1 depending if
the first operand is less than, equal or greater
than the second operand.

Change-Id: Ic0dedbad0ea2d918e0eeef9428859f0b54a6e7ad
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
diff --git a/drivers/gpu/msm/kgsl.c b/drivers/gpu/msm/kgsl.c
index a0a4056..e39a86d 100644
--- a/drivers/gpu/msm/kgsl.c
+++ b/drivers/gpu/msm/kgsl.c
@@ -215,7 +215,7 @@
 
 	/* Flush the freememontimestamp queue */
 	list_for_each_entry_safe(entry, entry_tmp, &device->memqueue, list) {
-		if (!timestamp_cmp(ts_processed, entry->free_timestamp))
+		if (timestamp_cmp(ts_processed, entry->free_timestamp) < 0)
 			break;
 
 		list_del(&entry->list);
@@ -303,7 +303,7 @@
 	ts_processed = device->ftbl->readtimestamp(device,
 		KGSL_TIMESTAMP_RETIRED);
 
-	return timestamp_cmp(ts_processed, timestamp);
+	return (timestamp_cmp(ts_processed, timestamp) >= 0);
 }
 EXPORT_SYMBOL(kgsl_check_timestamp);