IRDA: Fix global type conflicts in net/irda/irsysctl.c v2

The externs here didn't agree with the declarations in qos.c.

Better would be probably to move this into a header, but since it's
common practice to have naked externs with sysctls I left it for now.

Cc: samuel@sortiz.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>