[POWERPC] spufs: fix missing error handling in module_init()

spufs module_init forgot to call a few cleanup functions
on error path. This patch also includes cosmetic changes in
spu_sched_init() (identation fix and return error code).

[modified by hch to apply ontop of the latest schedule changes]

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Akinobu Mita <mita@fixstars.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>