coff: free malloc'd memory on successful target match too

coff: free malloc'd memory on successful target match too

object_p functions cannot allocate memory by malloc and not free it
before returning.  Even a successful target match may not be the best
match.  If a match isn't used then those malloc'd blocks won't be
freed.

	* coffgen.c (coff_real_object_p): Free malloc'd memory on target
	match too.