Restore the ERR_FATAL_ERROR() macro

Commit 0cd0a820

 removed this macro
along with many unused function and reason codes; ERR_FATAL_ERROR()
was not used in the tree, but did have external consumers.

Add it back to restore the API compatibility and avoid breaking
applications for no internal benefit.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2049)