staging/lustre/libcfs: drop bogus Kconfig default

Commit 4b5b4c7222 ("staging/lustre/libcfs: restore LINVRNT") added
"default false" to this Kconfig file. It was obviously meant to use
"default n" here. But we might as well drop this line, as a Kconfig bool
defaults to 'n' anyway.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>