nilfs2: use the BITS_PER_LONG macro

The macros NILFS_BMAP_KEY_BIT and NILFS_BMAP_NEW_PTR_INIT calculate,
within their definitions, the number of bits in an unsigned long variable.
Use the BITS_PER_LONG macro to make them simpler.

Link: https://lkml.kernel.org/r/20240826174116.5008-3-konishi.ryusuke@gmail.comSigned-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Huang Xiaojia <huangxiaojia2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

fs/nilfs2/bmap.h

@@ -87,9 +87,8 @@ struct nilfs_bmap_operations {
 
 
 #define NILFS_BMAP_SIZE		(NILFS_INODE_BMAP_SIZE * sizeof(__le64))
-#define NILFS_BMAP_KEY_BIT	(sizeof(unsigned long) * 8 /* CHAR_BIT */)
-#define NILFS_BMAP_NEW_PTR_INIT	\
-	(1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
+#define NILFS_BMAP_KEY_BIT	BITS_PER_LONG
+#define NILFS_BMAP_NEW_PTR_INIT	(1UL << (BITS_PER_LONG - 1))
 
 static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
 {