include/linux/bootmem.h: cleanup the comment for BOOTMEM_ flags

Use BOOTMEM_DEFAULT instead of 0 in the comment.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/bootmem.h

@@ -58,9 +58,9 @@ extern void free_bootmem_late(unsigned long physaddr, unsigned long size);
  * Flags for reserve_bootmem (also if CONFIG_HAVE_ARCH_BOOTMEM_NODE,
  * the architecture-specific code should honor this).
  *
- * If flags is 0, then the return value is always 0 (success). If
- * flags contains BOOTMEM_EXCLUSIVE, then -EBUSY is returned if the
- * memory already was reserved.
+ * If flags is BOOTMEM_DEFAULT, then the return value is always 0 (success).
+ * If flags contains BOOTMEM_EXCLUSIVE, then -EBUSY is returned if the memory
+ * already was reserved.
  */
 #define BOOTMEM_DEFAULT		0
 #define BOOTMEM_EXCLUSIVE	(1<<0)