fs/befs/linuxvfs.c: remove useless befs_error

Remove befs_error since when kmalloc fails there is a generic out of
memory and stack dump.

Link: http://lkml.kernel.org/r/3de4d388d98bbb570462a5eb8e64623e17fb5d74.1464226521.git.salah.triki@acm.org


Signed-off-by: Salah Triki <salah.triki@acm.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>