[PATCH] powerpc: fix booke user_disable_single_step()

[Josh Boyer]

On Wed, Jul 08, 2009 at 06:46:18PM -0500, Dave Kleikamp wrote:
>On booke processors, gdb is seeing spurious SIGTRAPs when setting a
>watchpoint.
>
>user_disable_single_step() simply quits when the DAC is non-zero.  It should
>be clearing the DBCR0_IC and DBCR0_BT bits from the dbcr0 register and
>TIF_SINGLESTEP from the thread flag.
>
>Signed-off-by: Dave Kleikamp <shaggy at linux.vnet.ibm.com>

I'll test this first thing in the morning.  At first glance it looks pretty
good.

josh