Fix comment about obsolete NOBBM.

Change-Id: Id35beced81336a5ac0f29cc3bfcda8ddbac88fcc
diff --git a/src/mm.c b/src/mm.c
index e728aac..06f38c2 100644
--- a/src/mm.c
+++ b/src/mm.c
@@ -272,7 +272,7 @@
 
 	/*
 	 * We need to do the break-before-make sequence if both values are
-	 * present, and if it hasn't been inhibited by the NOBBM flag.
+	 * present and the TLB is being invalidated.
 	 */
 	if (((flags & MM_FLAG_STAGE1) || mm_stage2_invalidate) &&
 	    arch_mm_pte_is_valid(v, level) &&