Style enum obj_type

Put each type into dedicated line, which makes addition of new
types cleaner.

Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D30070

sys/vm/vm.h

@@ -88,8 +88,16 @@ typedef u_char vm_prot_t;	/* protection codes */
 #define VM_PROT_RW		(VM_PROT_READ|VM_PROT_WRITE)
 #define	VM_PROT_DEFAULT		VM_PROT_ALL
 
-enum obj_type { OBJT_DEFAULT, OBJT_SWAP, OBJT_VNODE, OBJT_DEVICE, OBJT_PHYS,
-		OBJT_DEAD, OBJT_SG, OBJT_MGTDEVICE };
+enum obj_type {
+	OBJT_DEFAULT,
+	OBJT_SWAP,
+	OBJT_VNODE,
+	OBJT_DEVICE,
+	OBJT_PHYS,
+	OBJT_DEAD,
+	OBJT_SG,
+	OBJT_MGTDEVICE,
+};
 typedef u_char objtype_t;
 
 union vm_map_object;