s390/ptrace: get rid of long longs in psw_bits

The long longs were introduced by me in order to have a working
definition of the struct psw_bits also in 31 bit mode. Since that is
gone also get rid of the long longs.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>