[SCSI] mptfusion: Fix memory leak in mptctl_getiocinfo()

A 'kfree(karg)' is missing in a failure path in
mptctl.c::mptctl_getiocinfo() which can cause a memory leak.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: "Desai, Kashyap" <Kashyap.Desai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>