If the change of personality does not lead to change of exec domain,
__set_personality() returned without releasing the module reference
acquired by lookup_exec_domain().

Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>