[MTD] [TESTS] Fix some size_t printk format warnings

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/tests/mtd_torturetest.c b/drivers/mtd/tests/mtd_torturetest.c
index 2928d9e..631a0ab 100644
--- a/drivers/mtd/tests/mtd_torturetest.c
+++ b/drivers/mtd/tests/mtd_torturetest.c
@@ -450,7 +450,7 @@
 		printk("-------------------------------------------------------"
 		       "----------------------------------\n");
 
-		printk(PRINT_PREF "Page %d has %d bytes/%d bits failing verify,"
+		printk(PRINT_PREF "Page %zd has %d bytes/%d bits failing verify,"
 		       " starting at offset 0x%x\n",
 		       (mtd->erasesize - check_len + i) / pgsize,
 		       bytes, bits, first);