OpenSSL 1.1: libbitcoinconsensus_la-ecwrapper BN_zero_ex(zero) void to bool #6994

ODroid XU4 (ARM) Ubuntu 15.04 OpenSSL 1.1.0-dev native host compilation (not cross)

  CXX      libbitcoinconsensus_la-eccryptoverify.lo
  CXX      libbitcoinconsensus_la-ecwrapper.lo
In file included from ecwrapper.cpp:10:0:
ecwrapper.cpp: In function 'int {anonymous}::ECDSA_SIG_recover_key_GFp(EC_KEY*, ECDSA_SIG*, const unsigned char*, int, int, int)':
ecwrapper.cpp:91:10: error: could not convert 'BN_zero_ex(zero)' from 'void' to 'bool'
     if (!BN_zero(zero)) { ret=-1; goto err; }
          ^
ecwrapper.cpp:91:10: error: in argument to unary !
At global scope:
cc1plus: warning: unrecognized command line option "-Wno-self-assign"
Makefile:5803: recipe for target 'libbitcoinconsensus_la-ecwrapper.lo' failed
make[2]: *** [libbitcoinconsensus_la-ecwrapper.lo] Error 1

config.log

...
configure:26130: $PKG_CONFIG --exists --print-errors "libssl"
configure:26133: $? = 0
configure:26171: result: yes
...
configure:27040: checking openssl/ec.h usability
configure:27040: g++ -c -g -O2 -Wall -Wextra -Wformat -Wformat-security -Wno-unused-parameter -Wno-self-assign -I/usr/local/include  -I/usr/local/include   -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS -D_FILE_OFFSET_BITS=64 conftest.cpp >&5
configure:27040: $? = 0
configure:27040: result: yes
configure:27040: checking openssl/ec.h presence
configure:27040: g++ -E  -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS -D_FILE_OFFSET_BITS=64 conftest.cpp
configure:27040: $? = 0
configure:27040: result: yes
configure:27040: checking for openssl/ec.h
configure:27040: result: yes
...
ac_cv_header_openssl_ec_h=yes
...
pkg_cv_SSL_CFLAGS='-I/usr/local/include '
pkg_cv_SSL_LIBS='-L/usr/local/lib -lssl '
...
SSL_CFLAGS='-I/usr/local/include '
SSL_LIBS='-L/usr/local/lib -lssl '

*Same git source built fine on Ubuntu 15.10 for AMD64 EDIT: *but didn't self-build openssl 1.1 on AMD64

$ grep -r BN_zero /usr/local/ssl/
/usr/local/ssl/include/openssl/bn.h:void BN_zero_ex(BIGNUM *a);
/usr/local/ssl/include/openssl/bn.h:#  define BN_zero(a)      BN_zero_ex(a)
/usr/local/ssl/include/openssl/bn.h:#  define BN_zero(a)      (BN_set_word((a),0))

EDIT:

BN_zero() only needs to set 'top' and 'neg' to zero for correct results,
     and this should never fail. So the return value from the use of
     BN_set_word() (which can fail due to needless expansion) is now deprecated;
     if OPENSSL_NO_DEPRECATED is defined, BN_zero() is a void macro.

*https://www.openssl.org/news/changelog.html

Is this still relevant after #6954?

No