[S390] Remove unncessary export of arch_pick_mmap_layout
[S390] Remove unncessary export of arch_pick_mmap_layout

This function is defined for use in exec, not in modules.
No other architecture exports its implementation.

Signed-off-by: Ben Hutchings <73675debcd8a436be48ec22211dcf44fe0df0a64@decadent.org.uk>
Signed-off-by: Martin Schwidefsky <52616596d8f5df0d597e85ab515377f92f939c68@de.ibm.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas