kexec: remove never used member destination in kimage

struct kimage has a member destination which is used to store the real
destination address of each page when load segment from user space buffer
to kernel.  But we never retrieve the value stored in kimage->destination,
so this member variable in kimage and its assignment operation are
redundent code.

I guess for_each_kimage_entry just does the work that kimage->destination
is expected to do.

So in this patch just make a cleanup to remove it.
Signed-off-by: NBaoquan He <bhe@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/kexec.h

@@ -122,8 +122,6 @@ struct kimage {
 	kimage_entry_t *entry;
 	kimage_entry_t *last_entry;
 
-	unsigned long destination;
-
 	unsigned long start;
 	struct page *control_code_page;
 	struct page *swap_page;

kernel/kexec.c

@@ -856,8 +856,6 @@ static int kimage_set_destination(struct kimage *image,
 
 	destination &= PAGE_MASK;
 	result = kimage_add_entry(image, destination | IND_DESTINATION);
-	if (result == 0)
-		image->destination = destination;
 
 	return result;
 }
@@ -869,8 +867,6 @@ static int kimage_add_page(struct kimage *image, unsigned long page)
 
 	page &= PAGE_MASK;
 	result = kimage_add_entry(image, page | IND_SOURCE);
-	if (result == 0)
-		image->destination += PAGE_SIZE;
 
 	return result;
 }