Avoid converting void * to a function pointer when NULL is defined as
((void *)0), by have a 0 instead.

crypto/x509v3/v3_enum.c

diff --git a/crypto/x509v3/v3_enum.c b/crypto/x509v3/v3_enum.c
index f927110..aecfdc8 100644
--- a/crypto/x509v3/v3_enum.c
+++ b/crypto/x509v3/v3_enum.c
@@ -79,7 +79,7 @@
 (X509V3_EXT_D2I)d2i_ASN1_ENUMERATED,
 (X509V3_EXT_I2D)i2d_ASN1_ENUMERATED,
 (X509V3_EXT_I2S)i2s_ASN1_ENUMERATED_TABLE,
-(X509V3_EXT_S2I)NULL,
+(X509V3_EXT_S2I)0,
 NULL, NULL, NULL, NULL, crl_reasons};
 
 

crypto/x509v3/v3_int.c

diff --git a/crypto/x509v3/v3_int.c b/crypto/x509v3/v3_int.c
index a2edfe5..63c201e 100644
--- a/crypto/x509v3/v3_int.c
+++ b/crypto/x509v3/v3_int.c
@@ -67,6 +67,6 @@
 (X509V3_EXT_D2I)d2i_ASN1_INTEGER,
 (X509V3_EXT_I2D)i2d_ASN1_INTEGER,
 (X509V3_EXT_I2S)i2s_ASN1_INTEGER,
-(X509V3_EXT_S2I)NULL,
+(X509V3_EXT_S2I)0,
 NULL, NULL, NULL, NULL, NULL};