minix: fix regression in minix_mkdir()

Commit 9eed1fb7 ("minix: replace inode uid,gid,mode init with helper")
broke directory creation on minix filesystems.

Fix it by passing the needed mode flag to inode init helper.

Signed-off-by: Jorge Boncompte [DTI2] <jorge@dti2.net>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@kernel.org>		[2.6.35.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>