We can't stringify something the parser doesn't handle

The size needs to be written out in full.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/os.h b/os.h
index da80fbd..85db5b8 100644
--- a/os.h
+++ b/os.h
@@ -51,7 +51,7 @@
 #define SHM_HUGETLB			0
 #define FIO_HUGE_PAGE			0
 #else
-#define FIO_HUGE_PAGE			(4096 * 1024)
+#define FIO_HUGE_PAGE			4194304
 #endif
 
 #if __GNUC__ < 3