stress-mmaphuge: make size size_t to match mmap size argument

Signed-off-by: Colin Ian King <[email protected]>

stress-mmaphuge.c

@@ -64,7 +64,7 @@ typedef struct {
 
 typedef struct {
 	const int	flags;	/* MMAP flag */
-	const ssize_t	sz;	/* MMAP size */
+	const size_t	sz;	/* MMAP size */
 } stress_mmaphuge_setting_t;
 
 typedef struct {