um: Remove unused declarations from <as-layout.h>

_end is used, but it's already provided by <asm/sections.h>, so use that.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/include/shared/as-layout.h

@@ -44,7 +44,6 @@ struct cpu_task {
 
 extern struct cpu_task cpu_tasks[];
 
-extern unsigned long low_physmem;
 extern unsigned long high_physmem;
 extern unsigned long uml_physmem;
 extern unsigned long uml_reserved;
@@ -52,8 +51,6 @@ extern unsigned long end_vm;
 extern unsigned long start_vm;
 extern unsigned long long highmem;
 
-extern unsigned long _stext, _etext, _sdata, _edata, __bss_start, _end;
-extern unsigned long _unprotected_end;
 extern unsigned long brk_start;
 
 extern unsigned long host_task_size;

arch/um/kernel/um_arch.c

@@ -13,6 +13,7 @@
 #include <linux/sched.h>
 #include <asm/pgtable.h>
 #include <asm/processor.h>
+#include <asm/sections.h>
 #include <asm/setup.h>
 #include <as-layout.h>
 #include <arch.h>