powerpc/ps3: Remove duplicate error message

Remove a duplicate memory allocation failure error message.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1bc5a16a22c487c478a204ebb7b80a22d2ad9cd0.1585340156.git.geoff@infradead.org