[S390] tape: disable interrupts in tape_open and tape_release

Get tape device lock with interrupts disabled. Otherwise lockdep will issue a
warning similar to:

=================================
[ INFO: inconsistent lock state ]
2.6.27 #1
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inconsistent {in-hardirq-W} -> {hardirq-on-W} usage.
vol_id/2903 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (sch->lock){++..}, at: [<000003e00004c7a2>] tape_open+0x42/0x1a4 [tape]
{in-hardirq-W} state was registered at:
  [<000000000007ce5c>] __lock_acquire+0x894/0xa74
  [<000000000007d0ce>] lock_acquire+0x92/0xb8
  [<0000000000345154>] _spin_lock+0x5c/0x9c
  [<0000000000202264>] do_IRQ+0x124/0x1f0
  [<0000000000026610>] io_return+0x0/0x8

irq event stamp: 847
hardirqs last  enabled at (847): [<000000000007aca6>] trace_hardirqs_on+0x2a/0x38
hardirqs last disabled at (846): [<0000000000076ca2>] trace_hardirqs_off+0x2a/0x38
softirqs last  enabled at (0): [<000000000004909e>] copy_process+0x43e/0x11f4
softirqs last disabled at (0): [<0000000000000000>...