elf_core_copy_task_regs(): task_pt_regs is defined everywhere

Had been since 2011 for all live architectures, ever since 2013
for all architectures, period.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

include/linux/elfcore.h

@@ -88,7 +88,7 @@ static inline int elf_core_copy_task_regs(struct task_struct *t, elf_gregset_t*
 {
 #if defined (ELF_CORE_COPY_TASK_REGS)
 	return ELF_CORE_COPY_TASK_REGS(t, elfregs);
-#elif defined (task_pt_regs)
+#else
 	elf_core_copy_regs(elfregs, task_pt_regs(t));
 #endif
 	return 0;