Fix unused variable warning.HEADmastermain

Since nfences is only used in an assert, mark it as maybe unused.

Test: Builds without warnings.
Change-Id: I25cc42699781740e5335a67a8f48e2c883dba264

1 files changed, 2 insertions, 1 deletions

diff --git a/dlmalloc.c b/dlmalloc.c
index a61c0da..3eb761d 100644
--- a/dlmalloc.c
+++ b/dlmalloc.c
@@ -4009,7 +4009,8 @@ static void add_segment(mstate m, char* tbase, size_t tsize, flag_t mmapped) {
   msegmentptr ss = (msegmentptr)(chunk2mem(sp));
   mchunkptr tnext = chunk_plus_offset(sp, ssize);
   mchunkptr p = tnext;
-  int nfences = 0;
+  /* Only used in assert. */
+  [[maybe_unused]] int nfences = 0;
 
   /* reset top to new space */
   init_top(m, (mchunkptr)tbase, tsize - TOP_FOOT_SIZE);