drm/amdkfd: uninitialized variable in dbgdev_wave_control_set_registers()

drm/amdkfd: uninitialized variable in dbgdev_wave_control_set_registers()

BugLink: http://bugs.launchpad.net/bugs/1578798
commit 93fce954427effee89e44a976299b15dd75b4bbc upstream.

At the end of the function we expect "status" to be zero, but it's
either -EINVAL or uninitialized.

Fixes: 788bf83db301 ('drm/amdkfd: Add wave control operation to debugger')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>