ARM: vexpress/spc: Delete an error message for a failed memory allocation

Omit extra messages for a memory allocation failure in these functions.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>