MN10300: Change the fault handler to check in_atomic() not in_interrupt()

Change the MN10300 fault handler to make it check in_atomic() rather than
in_interrupt() as commit 6edaf68a did for other
architectures:

	Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
	Date:   Wed Dec 6 20:32:18 2006 -0800

	[PATCH] mm: arch do_page_fault() vs in_atomic()

	In light of the recent pagefault and filemap_copy_from_user work I've
	gone through all the arch pagefault handlers to make sure the
	inc_preempt_count() 'feature' works as expected.

	Several sections of code (including the new filemap_copy_from_user)
	rely on the fact that faults do not take locks under increased preempt
	count.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>