bash-completion: use '\n' as IFS when ask for filenames

The bash completion for more(1) treats the space-separated pieces of
filenames as different files.

	$ touch foo\ bar
	$ more foo<TAB>
	bar foo

Reported-by: Ángel González <ingenit@zoho.com>
Signed-off-by: Karel Zak <kzak@redhat.com>