NCP: delete test of long-deceased CONFIG_NCPFS_DEBUGDENTRY

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Acked-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>