mtd: mtd_nandecctest: make module_init() return appropriate errno

Return -EINVAL instead of -1 (-EPERM) when test fails.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/tests/mtd_nandecctest.c

@@ -51,7 +51,7 @@ static int nand_ecc_test(const size_t size)
 	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 16, 4,
 			error_data, size, false);
 
-	return -1;
+	return -EINVAL;
 }
 
 #else