Add missing ForceZero in PKCS#12

[Frauschi]

Identified by Uday Devaraj, SYNE Lab, Syracuse University. Fixes (re-opened) zd21977.

[github-actions]

MemBrowse Memory Report

gcc-arm-cortex-m4-crypto-only

• FLASH: .text +64 B (+0.0%, 174,504 B / 262,144 B, total: 67% used)

gcc-arm-cortex-m4-openssl-compat

• FLASH: .text +64 B (+0.0%, 770,892 B / 1,048,576 B, total: 74% used)

stm32-sim-stm32h753

• FLASH: .text +64 B (+0.0%, 183,460 B / 2,097,152 B, total: 9% used)
  No memory changes detected for:
• gcc-arm-cortex-m0plus
• gcc-arm-cortex-m3
• gcc-arm-cortex-m4
• gcc-arm-cortex-m4-baremetal
• gcc-arm-cortex-m4-dtls13
• gcc-arm-cortex-m4-min-ecc
• gcc-arm-cortex-m4-pkcs7
• gcc-arm-cortex-m4-pq
• gcc-arm-cortex-m4-rsa-only
• gcc-arm-cortex-m4-sp-math
• gcc-arm-cortex-m4-tls12
• gcc-arm-cortex-m4-tls13
• gcc-arm-cortex-m7
• gcc-arm-cortex-m7-pq
• gcc-arm-cortex-m7-tls13
• linuxkm-pie
• linuxkm-standard

[Frauschi]

Jenkins retest this please