Use "ifdef" rather than "if" to test for __KERNEL__

Both work, but the latter can cause warnings in user space
from compilers that don't like using undefined identifiers
in preprocessor expressions (quite reasonable).

Pointed out by Randy Dunlap.

include/asm-ia64/sn/sn2/shubio.h

@@ -3384,7 +3384,7 @@ typedef ii_icrb0_e_u_t icrbe_t;
 
 #define IO_PERF_SETS	32
 
-#if __KERNEL__
+#ifdef __KERNEL__
 #include <asm/sn/dmamap.h>
 #include <asm/sn/driver.h>
 #include <asm/sn/xtalk/xtalk.h>

include/asm-ia64/sn/xtalk/xtalk.h

@@ -55,7 +55,7 @@ typedef struct xtalk_piomap_s *xtalk_piomap_t;
 /*
  * Kernel/driver only definitions
  */
-#if __KERNEL__
+#ifdef __KERNEL__
 
 #include <asm/types.h>
 #include <asm/sn/types.h>

include/asm-ia64/sn/xtalk/xwidget.h

@@ -183,7 +183,7 @@ typedef struct xwidget_hwid_s {
 
 
 /* Generic crosstalk widget initialization interface */
-#if __KERNEL__
+#ifdef __KERNEL__
 
 extern int              xwidget_driver_register(xwidget_part_num_t part_num,
 						xwidget_mfg_num_t mfg_num,

include/linux/kobject.h

@@ -15,7 +15,7 @@
 #ifndef _KOBJECT_H_
 #define _KOBJECT_H_
 
-#if __KERNEL__
+#ifdef __KERNEL__
 
 #include <linux/types.h>
 #include <linux/list.h>

include/linux/kref.h

@@ -15,7 +15,7 @@
 #ifndef _KREF_H_
 #define _KREF_H_
 
-#if __KERNEL__
+#ifdef __KERNEL__
 
 #include <linux/types.h>
 #include <asm/atomic.h>