powerpc/pseries: Delete an error message for a failed string duplication in dlpar_store()

Omit an extra message for a memory allocation failure in this function.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Acked-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/535cfec2-782f-61ec-f6fb-c50186ead2af@web.de