x86: have set_memory_array_{uc,wb} coalesce memtypes, fix

Fix the start addr for free_memtype calls in the error path.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Rene Herman <rene.herman@keyaccess.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>