paicrypt_init() return incorrect error code in case the number
of PAI crypto counters is too high. Change the return code to
-E2BIG.

Please merge with d0b0efedc7fe
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>