s390: do not clobber personality flags in sys_32_personality()
s390: do not clobber personality flags in sys_32_personality()

There are multiple errors in how sys_32_personality() handles personality
flags stored in top three bytes.

- directly comparing current->personality against PER_LINUX32 doesn't work
  in cases when any of the personality flags stored in the top three bytes
  are used.
- directly forcefully setting personality to PER_LINUX32 or PER_LINUX
  discards any flags stored in the top three bytes

Fix the first one by properly using personality() macro to compare only
PER_MASK bytes.
Fix the second one by setting only the bits that should be set, instead of
overwriting the whole value.

Signed-off-by: Jiri Kosina <ed58f755cc8caaf10c3e8c731a8b86fb8f13d6cb@suse.cz>
Signed-off-by: Heiko Carstens <8dcf0f69152f32f23184f83357a3731522e56b9c@de.ibm.com>
Signed-off-by: Martin Schwidefsky <52616596d8f5df0d597e85ab515377f92f939c68@de.ibm.com>

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