Rename MBEDTLS_X509_INFO to !MBEDTLS_X509_REMOVE_INFO

The introduction of positive options to control the presence
of pre-existing functionality breaks the build for users of
handwritten configurations.

Signed-off-by: Hanno Becker <hanno.becker@arm.com>
diff --git a/programs/x509/req_app.c b/programs/x509/req_app.c
index df1dba8..351dd16 100644
--- a/programs/x509/req_app.c
+++ b/programs/x509/req_app.c
@@ -36,12 +36,12 @@
 
 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_RSA_C) ||  \
     !defined(MBEDTLS_X509_CSR_PARSE_C) || !defined(MBEDTLS_FS_IO) || \
-    !defined(MBEDTLS_X509_INFO)
+    !!defined(MBEDTLS_X509_REMOVE_INFO)
 int main( void )
 {
     mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_RSA_C and/or "
            "MBEDTLS_X509_CSR_PARSE_C and/or MBEDTLS_FS_IO and/or "
-           "MBEDTLS_X509_INFO not defined.\n");
+           "MBEDTLS_X509_REMOVE_INFO not defined.\n");
     mbedtls_exit( 0 );
 }
 #else