mm/sparse: add the missing sparse_buffer_fini() in error branch

mm/sparse: add the missing sparse_buffer_fini() in error branch

sparse_buffer_init() and sparse_buffer_fini() should appear in pair, or a
WARN issue would be through the next time sparse_buffer_init() runs.

Add the missing sparse_buffer_fini() in error branch.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 85c77f791390 ("mm/sparse: add new sparse_init_nid() and sparse_init()")
Signed-off-by: Wang Wensheng <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Reviewed-by: Oscar Salvador <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>