Fix Coverity 1520485: logically dead code

The check is unnecessary as the condition is already checked
before the switch statement.

Reviewed-by: Hugo Landau <hlandau@openssl.org>
Reviewed-by: David von Oheimb <david.von.oheimb@siemens.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/20121)

crypto/cmp/cmp_ctx.c

@@ -919,13 +919,9 @@ int OSSL_CMP_CTX_set_option(OSSL_CMP_CTX *ctx, int opt, int val)
         ctx->keep_alive = val;
         break;
     case OSSL_CMP_OPT_MSG_TIMEOUT:
-        if (val < 0)
-            val = 0;
         ctx->msg_timeout = val;
         break;
     case OSSL_CMP_OPT_TOTAL_TIMEOUT:
-        if (val < 0)
-            val = 0;
         ctx->total_timeout = val;
         break;
     case OSSL_CMP_OPT_PERMIT_TA_IN_EXTRACERTS_FOR_IR: