This patch fixes this error:

  CC      arch/um/kernel/smp.o
In file included from /home/wangcong/projects/linux-2.6/arch/um/kernel/smp.c:9:
include2/asm/tlb.h: In function ¡®tlb_remove_page¡¯:
include2/asm/tlb.h:101: error: implicit declaration of function ¡®page_cache_release¡¯
make[2]: *** [arch/um/kernel/smp.o] Error 1
make[1]: *** [arch/um/kernel] Error 2
make: *** [sub-make] Error 2

And since including <linux/pagemap.h> in <linux/swap.h> will break sparc,
we add this #include in uml's own header.

Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: WANG Cong <wangcong@zeuux.org>

---
diff --git a/include/asm-um/tlb.h b/include/asm-um/tlb.h
index 39fc475..5240fa1 100644
--- a/include/asm-um/tlb.h
+++ b/include/asm-um/tlb.h
@@ -1,6 +1,7 @@
 #ifndef __UM_TLB_H
 #define __UM_TLB_H
 
+#include <linux/pagemap.h>
 #include <linux/swap.h>
 #include <asm/percpu.h>
 #include <asm/pgalloc.h>