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/library/x509_crl.c b/library/x509_crl.c
index 4c898c9..dbaad7d 100644
--- a/library/x509_crl.c
+++ b/library/x509_crl.c
@@ -614,7 +614,7 @@
 }
 #endif /* MBEDTLS_FS_IO */
 
-#if defined(MBEDTLS_X509_INFO)
+#if !defined(MBEDTLS_X509_REMOVE_INFO)
 /*
  * Return an informational string about the certificate.
  */
@@ -694,7 +694,7 @@
 
     return( (int) ( size - n ) );
 }
-#endif /* MBEDTLS_X509_INFO */
+#endif /* MBEDTLS_X509_REMOVE_INFO */
 
 /*
  * Initialize a CRL chain