x86: Fix a memory leak in md_assemble

Fix a memory leak in md_assemble where copy may be cleared and may be
the same as copy:

      if (copy && !mnem_suffix)
        {
          line = copy;
          copy = NULL;
  no_match:

	* config/tc-i386.c (md_assemble): Properly free the xstrdup
	memory.
1 file changed