[IA64] unwind: remove preprocesser noise, and correct comment

The expression in the comment was mis-bracketted.
There was also no need to introduce a coding-style breaking
macro for a single use, so just made it a static const.

Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/unwind.c

@@ -1204,10 +1204,10 @@ desc_spill_sprel_p (unsigned char qp, unw_word t, unsigned char abreg, unw_word
 static inline unw_hash_index_t
 hash (unsigned long ip)
 {
-#	define hashmagic	0x9e3779b97f4a7c16UL	/* based on (sqrt(5)/2-1)*2^64 */
+	/* magic number = ((sqrt(5)-1)/2)*2^64 */
+	static const unsigned long hashmagic = 0x9e3779b97f4a7c16UL;
 
-	return (ip >> 4)*hashmagic >> (64 - UNW_LOG_HASH_SIZE);
-#undef hashmagic
+	return (ip >> 4) * hashmagic >> (64 - UNW_LOG_HASH_SIZE);
 }
 
 static inline long