sfxge(4): avoid necessity to add one more constant condition note

Use for forever loop instead of while.

Found by lint on illumos.

Submitted by:   Garrett D'Amore <garrett at damore.org>
Sponsored by:   Solarflare Communications, Inc.
MFC after:      1 week

sys/dev/sfxge/common/ef10_nvram.c

@@ -362,7 +362,7 @@ tlv_last_segment_end(
 	 * is no end tag then the previous segment was the last valid one,
 	 * so return the pointer to its end tag.
 	 */
-	while (1) {
+	for (;;) {
 		if (tlv_init_cursor(&segment_cursor, segment_start,
 		    cursor->limit, segment_start) != 0)
 			break;