[PATCH] Fix for minix crash

Mounting a (corrupt) minix filesystem with zero s_zmap_blocks
gives a spectacular crash on my 2.6.17.8 system, no doubt
because minix/inode.c does an unconditional
	minix_set_bit(0,sbi->s_zmap[0]->b_data);

[akpm@osdl.org: make labels conistent while we're there]

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>