Add {lib}_R_{lib}_LIB, for our engines and other "external" modules

Engines lacked the possibility to refer to themselves in this form:

    WHATEVERerr(WHATEVER_F_SOMETHING, WHATEVER_R_WHATEVER_LIB);

This little change makes that possible, and gets used in e_capi.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from #19301)

engines/e_capi_err.c

@@ -1,6 +1,6 @@
 /*
  * Generated by util/mkerr.pl DO NOT EDIT
- * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2022 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -92,3 +92,10 @@ static void ERR_CAPI_error(int function, int reason, const char *file, int line)
     ERR_raise(lib_code, reason);
     ERR_set_debug(file, line, NULL);
 }
+
+static int ERR_CAPI_lib(void)
+{
+    if (lib_code == 0)
+        lib_code = ERR_get_next_error_library();
+    return lib_code;
+}

engines/e_capi_err.h

@@ -1,6 +1,6 @@
 /*
  * Generated by util/mkerr.pl DO NOT EDIT
- * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2022 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -17,6 +17,7 @@
 
 
 # define CAPIerr(f, r) ERR_CAPI_error(0, (r), OPENSSL_FILE, OPENSSL_LINE)
+# define ERR_R_CAPI_LIB ERR_CAPI_lib()
 
 
 /*

util/mkerr.pl

@@ -1,5 +1,5 @@
 #! /usr/bin/env perl
-# Copyright 1999-2021 The OpenSSL Project Authors. All Rights Reserved.
+# Copyright 1999-2022 The OpenSSL Project Authors. All Rights Reserved.
 #
 # Licensed under the Apache License 2.0 (the "License").  You may not use
 # this file except in compliance with the License.  You can obtain a copy
@@ -450,6 +450,7 @@ sub help
         } else {
             print OUT <<"EOF";
 # define ${lib}err(f, r) ERR_${lib}_error(0, (r), OPENSSL_FILE, OPENSSL_LINE)
+# define ERR_R_${lib}_LIB ERR_${lib}_lib()
 
 EOF
             if ( ! $static ) {
@@ -629,6 +630,13 @@ sub help
     ERR_raise(lib_code, reason);
     ERR_set_debug(file, line, NULL);
 }
+
+${st}int ERR_${lib}_lib(void)
+{
+    if (lib_code == 0)
+        lib_code = ERR_get_next_error_library();
+    return lib_code;
+}
 EOF
 
         }