ipmi: fix memleaking for add_smi when duplicating happen

Free the temporary info struct when we have duplicated ones.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Corey Minyard <minyard@acm.org>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>