s390/pkey: add one more argument space for debug feature entry

[ Upstream commit 6b1f16ba730d4c0cda1247568c3a1bf4fa3a2f2f ]

The debug feature entries have been used with up to 5 arguents
(including the pointer to the format string) but there was only
space reserved for 4 arguemnts. So now the registration does
reserve space for 5 times a long value.

This fixes a sometime appearing weired value as the last
value of an debug feature entry like this:

... pkey_sec2protkey zcrypt_send_cprb (cardnr=10 domain=12)
   failed with errno -2143346254

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reported-by: Christian Rund <Christian.Rund@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>