wext: remove seq_start/stop sparse annotations

Even though they are true, they cause sparse to complain
because it doesn't see the __acquires(dev_base_lock) on
dev_seq_start() because it is only added to the function
in net/core/dev.c, not the header file. To keep track of
the nesting correctly we should probably annotate those
functions publically, but for now let's just remove the
annotation I added to wext.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>