Updating erroneous documentation for BIO_get_mem_data and subsequent usage #3281

Job	Run time
grpc	24m 41s
ntp	1m 58s
tcpdump	1m 44s
haproxy	4m 29s
tpm2-tss	3m 40s
trousers	1m 20s
bind9	5m 13s
OpenLDAP	17m 12s
openvpn	3m 49s
socat	6m 31s
Python releases (FIPS=0 OPENSSL_IN_CRT=0)	11m 44s
Python main	3m 46s
strongswan	1m 47s
Python releases (FIPS=1 OPENSSL_IN_CRT=0)	12m 48s
Python releases (FIPS=0 OPENSSL_IN_CRT=1)	11m 33s
Python releases (FIPS=1 OPENSSL_IN_CRT=1)	11m 57s
amazon-corretto-crypto-provider	18m 40s
libevent	28m 49s
	2h 51m 41s

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