wl1251: fix sleep related error paths in wl1251_op_bss_info_changed()

In various cases wl1251_op_bss_info_changed() did not call elp_sleep()
after an error was noticed. Fix it by using correct goto label.

The bug was a theoretical one, in practise it doesn't matter because
if commands start returning errors there will be lots of other problems.

Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>