Fix HP_MALLOC build flag - DBG_MALLOC is not necessary for it

Style fix

Author: Shkiperon

mem/shm_mem.h

@@ -301,6 +301,7 @@ inline static void shm_threshold_check(void)
 				lock_release(mem_lock); \
 		} while (0)
 	#endif
+	extern unsigned long long *shm_hash_usage;
 #else
 #define shm_lock()    lock_get(mem_lock)
 #define shm_unlock()  lock_release(mem_lock)
@@ -629,8 +630,6 @@ inline static void _shm_free_bulk(void *ptr,
 #define shm_free_bulk( _ptr ) _shm_free_bulk( (_ptr), \
 	__FILE__, __FUNCTION__, __LINE__ )
 
-extern unsigned long long *shm_hash_usage;
-
 #else /*DBG_MALLOC*/
 
 #define shm_malloc_func shm_malloc