[PATCH] Allow mem=mmap to also use a file backing

We have the stuff in place for huge page backed memory, so it's little
extra code to support io buffers inside mmap file backed memory.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fio.h b/fio.h
index df36f14..d55a1e3 100644
--- a/fio.h
+++ b/fio.h
@@ -226,8 +226,8 @@
 	unsigned long long zone_size;
 	unsigned long long zone_skip;
 	enum fio_memtype mem_type;
-	char *hugefile;
-	int hugefd;
+	char *mmapfile;
+	int mmapfd;
 	unsigned int stonewall;
 	unsigned int numjobs;
 	unsigned int iodepth;