[PATCH] elfcore.h : Fix UML build breakage

[Parag Warudkar]

Commit a65e7bfcd74e4c0939f235d2bf9f48ddb3a57991 breaks UML build with 
below error - 

In file included from fs/proc/kcore.c:17:
include/linux/elfcore.h: In function ʽelf_core_copy_task_regsʼ:
include/linux/elfcore.h:129: error: implicit declaration of function 
ʽtask_pt_regsʼ

Fix this by restoring the previous behavior of returning 0 for all arches 
like UML that don't define task_pt_regs.

Signed-off-by: Parag Warudkar <parag.lkml@xxxxxxxxx>

diff --git a/include/linux/elfcore.h b/include/linux/elfcore.h
index 03ec167..28f722e 100644
--- a/include/linux/elfcore.h
+++ b/include/linux/elfcore.h
@@ -125,7 +125,7 @@ static inline int elf_core_copy_task_regs(struct task_struct *t, elf_gregset_t*
 #ifdef ELF_CORE_COPY_TASK_REGS
 	
 	return ELF_CORE_COPY_TASK_REGS(t, elfregs);
-#else
+#elif defined task_pt_regs
 	elf_core_copy_regs(elfregs, task_pt_regs(t));
 #endif
 	return 0;