coredump: get rid of coredump_params->written

cprm->written is redundant with cprm->file->f_pos, so use that instead.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 7d914c6..f5ce8f4 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -2273,7 +2273,7 @@
 		goto end_coredump;
 
 	/* Align to page */
-	if (!dump_skip(cprm, dataoff - cprm->written))
+	if (!dump_skip(cprm, dataoff - cprm->file->f_pos))
 		goto end_coredump;
 
 	for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;