bootstage: Warning if space is exhausted

At present bootstage silently ignores new records if it runs out of
space. It is sometimes obvious by looking at the report, but the IDs are
not contiguous, so it is easy to miss.

Aad a message so that action can be taken.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/bootstage.c b/common/bootstage.c
index 2c0110c..4621105 100644
--- a/common/bootstage.c
+++ b/common/bootstage.c
@@ -9,6 +9,8 @@
  * permits accurate timestamping of each.
  */
 
+#define LOG_CATEGORY	LOGC_BOOT
+
 #include <common.h>
 #include <bootstage.h>
 #include <hang.h>
@@ -127,12 +129,16 @@
 
 	/* Only record the first event for each */
 	rec = find_id(data, id);
-	if (!rec && data->rec_count < RECORD_COUNT) {
-		rec = &data->record[data->rec_count++];
-		rec->time_us = mark;
-		rec->name = name;
-		rec->flags = flags;
-		rec->id = id;
+	if (!rec) {
+		if (data->rec_count < RECORD_COUNT) {
+			rec = &data->record[data->rec_count++];
+			rec->time_us = mark;
+			rec->name = name;
+			rec->flags = flags;
+			rec->id = id;
+		} else {
+			log_warning("Bootstage space exhasuted\n");
+		}
 	}
 
 	/* Tell the board about this progress */