acl: include quote.h These files use quote(), so include quote.h for it otherwise we fail to build with errors like: copy-acl.c: In function 'copy_acl': copy-acl.c:51:7: error: implicit declaration of function 'quote' [-Werror=implicit-function-declaration] * lib/copy-acl.c: Include quote.h. * lib/set-acl.c: Likewise. Signed-off-by: Eric Blake <eblake@redhat.com>