drm/amdkfd: Unwind debug trap enable on copy_to_user failure

drm/amdkfd: Unwind debug trap enable on copy_to_user failure

If kfd_dbg_trap_enable() fails while copying runtime_info to userspace,
it had already activated the trap, set debug_trap_enabled, taken an extra
process reference, and opened the debug event file. Return -EFAULT without
unwinding that state, leaving inconsistent trap state and a refcount
imbalance that could break later DISABLE/ENABLE.

On copy_to_user failure, deactivate the trap and undo the rest of the
enable setup before returning.

Signed-off-by: Yongqiang Sun <Yongqiang.Sun@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>