coredump: update coredump-related headers

Create a new header file, fs/coredump.h, which contains functions only
used by the new coredump.c.  It also moves do_coredump to the
include/linux/coredump.h header file, for consistency.

Signed-off-by: Alex Kelly <alex.page.kelly@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/coredump.c

@@ -14,6 +14,7 @@
 #include <linux/key.h>
 #include <linux/personality.h>
 #include <linux/binfmts.h>
+#include <linux/coredump.h>
 #include <linux/utsname.h>
 #include <linux/pid_namespace.h>
 #include <linux/module.h>
@@ -39,6 +40,7 @@
 
 #include <trace/events/task.h>
 #include "internal.h"
+#include "coredump.h"
 
 #include <trace/events/sched.h>