[SCSI] sym53c8xx: fix bad memset argument in sym_set_cam_result_error

On a big powerpc box I got the following oops with 2.6.24-git2:

sym0: <1010-66> rev 0x1 at pci 0000:d0:01.0 irq 215
sym0: No NVRAM, ID 7, Fast-80, LVD, parity checking
sym0: SCSI BUS has been reset.
scsi0 : sym-2.2.3
 target0:0:8: FAST-40 WIDE SCSI 80.0 MB/s ST (25 ns, offset 31)
scsi 0:0:8:0: Direct-Access     IBM      ST318305LC       C509 PQ: 0
ANSI: 3
 target0:0:8: tagged command queuing enabled, command queue depth 16.
 target0:0:8: Beginning Domain Validation
 target0:0:8: asynchronous
 target0:0:8: wide asynchronous
 target0:0:8: FAST-80 WIDE SCSI 160.0 MB/s DT (12.5 ns, offset 31)
 target0:0:8: FAST-80 WIDE SCSI 160.0 MB/s DT (12.5 ns, offset 31)
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc000000000038460
cpu 0x25: Vector: 300 (Data Access) at [c00000000f567840]
    pc: c000000000038460: .memcpy+0x60/0x280
    lr: d000000000050280: .sym_set_cam_result_error+0xfc/0x1e0 [sym53c8xx]
    sp: c00000000f567ac0
   msr: 8000000000009032
   dar: 0
 dsisr: 42000000
  current = 0xc000006d1e0af0a0
  paca    = 0xc0000000004afc00
    pid   = 0, comm = swapper
enter ? for help
[link register   ] d000000000050280
.sym_set_cam_result_error+0xfc/0x1e0 [sym53c8xx]
[c00000000f567ac0] c00000000f567b80 (unreliable)
[c00000000f567b80] d0000000000552b8 .sym_complete_error+0x12c/0x1bc [sym53c8xx]
[c00000000f567c20] d0000000000561a4 .sym_int_sir+0xaa4/0x1718 [sym53c8xx]
[c00000000f567d00] d000000000057e8c .sym_interrupt+0x4e4/0x6ec [sym53c8xx]
[c00000000f567dc0] d00000000004fdf4 .sym53c8xx_intr+0x6c/0xdc [sym53c8xx]
[c00000000f567e50] c0000000000a83e0 .handle_IRQ_event+0x7c/0xec
[c00000000f567ef0] c0000000000aa344 .handle_fasteoi_irq+0x130/0x1f0
[c00000000f567f90] c00000000002a538 .call_handle_irq+0x1c/0x2c
[c000004d5e0b3a90] c00000000000c320 .do_IRQ+0x108/0x1d0
[c000004d5e0b3b20] c000000000004790 hardware_interrupt_entry+0x18/0x1c

The memset() in sym_set_cam_result_error() would appear to be trashing
the scsi_cmnd struct instead of clearing sense_buffer.

Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>