USB: isp1362-hcd, fix double lock

Stanse found that isp1362_sw_reset tries to take a isp1362_hcd->lock,
but it is already held in isp1362_hc_stop. Avoid that by introducing
__isp1362_sw_reset which doesn't take the lock and call it from
isp1362_hc_stop. isp1362_sw_reset is then as simple as lock --
__isp1362_sw_reset -- unlock.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Lothar Wassmann <LW@KARO-electronics.de>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>