Fix cstyle warnings

This patch contains no functional changes.  It is solely intended
to resolve cstyle warnings in order to facilitate moving the spl
source code in to the zfs repository.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #681

include/vm/anon.h

@@ -23,6 +23,6 @@
  */
 
 #ifndef _SPL_VM_ANON_H
-#define _SPL_VM_ANON_H
+#define	_SPL_VM_ANON_H
 
 #endif /* SPL_VM_ANON_H */

include/vm/pvn.h

@@ -23,6 +23,6 @@
  */
 
 #ifndef _SPL_VM_PVN_H
-#define _SPL_VM_PVN_H
+#define	_SPL_VM_PVN_H
 
 #endif /* SPL_VM_PVN_H */

include/vm/seg_kmem.h

@@ -23,7 +23,7 @@
  */
 
 #ifndef _SPL_SEG_KMEM_H
-#define _SPL_SEG_KMEM_H
+#define	_SPL_SEG_KMEM_H
 
 #include <sys/vmsystm.h>