cxlflash: Correct trace string

The trace following the failure of alloc_mem() incorrectly identifies
which function failed. This can lead to misdiagnosing a failure.

Fix the string to correctly indicate that alloc_mem() failed.

Reported-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>