[sysprof] util: use ifdef instead of if defined

[Christian Hergert <chergert src gnome org>]

commit 3cfcee4757161fb3e7fe427b6059aa0977c28633
Author: Christian Hergert <chergert redhat com>
Date:   Mon Aug 22 11:53:58 2016 -0700

    util: use ifdef instead of if defined

 lib/util/util.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/lib/util/util.h b/lib/util/util.h
index 591722d..b0b55db 100644
--- a/lib/util/util.h
+++ b/lib/util/util.h
@@ -1,11 +1,11 @@
 #ifndef SP_UTIL_H
 #define SP_UTIL_H
 
-#if defined(__i386__)
+#ifdef __i386__
 #define read_barrier()           asm volatile("lock; addl $0,0(%%esp)" ::: "memory")
 #endif
 
-#if defined(__x86_64__)
+#ifdef __x86_64__
 #define read_barrier()           asm volatile("lfence" ::: "memory")
 #endif