8250: Fix lock warning (and possible crash)

Splitting the 8250 code back up to avoid a clash with the NR_IRQS removal
patch introduced a last minute bug. Put back the additional needed lines
for the old lock init

Signed-off-by: Alan Cox <alan@redhat.com>
[ Ingo also reports that this can cause a spontaneous reboot crash with
  certain configs, and sends in an identical patch ]
Tested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>