Mark bitrevX() functions as const

[David Howells <dhowells@redhat.com>]

Mark the bit reversal functions as being const as they always return the same
output for any given input.

Signed-Off-By: David Howells <dhowells@redhat.com>
---

 include/linux/bitrev.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h
index 05e540d..032056b 100644
--- a/include/linux/bitrev.h
+++ b/include/linux/bitrev.h
@@ -5,11 +5,11 @@ #include <linux/types.h>
 
 extern u8 const byte_rev_table[256];
 
-static inline u8 bitrev8(u8 byte)
+static inline __attribute__((const)) u8 bitrev8(u8 byte)
 {
 	return byte_rev_table[byte];
 }
 
-extern u32 bitrev32(u32 in);
+extern __attribute__((const)) u32 bitrev32(u32 in);
 
 #endif /* _LINUX_BITREV_H */