pam: avoid compiler warning in copyIntoSecret()
pam: avoid compiler warning in copyIntoSecret()

gcc 11 enabled -Wmaybe-uninitialized by default.  It causes a
false-positive warning in copyIntoSecret() because gcc doesn't
understand that mlock() is special and doesn't read from the memory.

Just initialize the memory to avoid this warning.

google/fscrypt,google/fscrypt,google/fscrypt