[POWERPC] spufs: Correctly calculate the size of the local-store to dump

The routine to dump the local store, __spufs_mem_read(), does not take the
spu_lslr_RW value into account - so we shouldn't check it when we're
calculating the size either.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>