env: add the same prefix to error messages to make it detectable by tests

The error message should start with `## Error: ` so that it's easily
detectable by tests without needing to have a complex regexp for
matching all possible error message patterns.

Let's add the `## Error: ` prefix to the error messages since it's the
one already in use.

Suggested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Quentin Schulz <quentin.schulz@bootlin.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>

cmd/nvedit.c

@@ -960,7 +960,8 @@ NXTARG:		;
 				H_MATCH_KEY | H_MATCH_IDENT,
 				&ptr, size, argc, argv);
 		if (len < 0) {
-			pr_err("Cannot export environment: errno = %d\n", errno);
+			pr_err("## Error: Cannot export environment: errno = %d\n",
+			       errno);
 			return 1;
 		}
 		sprintf(buf, "%zX", (size_t)len);
@@ -980,7 +981,8 @@ NXTARG:		;
 			H_MATCH_KEY | H_MATCH_IDENT,
 			&res, ENV_SIZE, argc, argv);
 	if (len < 0) {
-		pr_err("Cannot export environment: errno = %d\n", errno);
+		pr_err("## Error: Cannot export environment: errno = %d\n",
+		       errno);
 		return 1;
 	}
 
@@ -995,7 +997,8 @@ NXTARG:		;
 	return 0;
 
 sep_err:
-	printf("## %s: only one of \"-b\", \"-c\" or \"-t\" allowed\n",	cmd);
+	printf("## Error: %s: only one of \"-b\", \"-c\" or \"-t\" allowed\n",
+	       cmd);
 	return 1;
 }
 #endif
@@ -1115,7 +1118,8 @@ static int do_env_import(cmd_tbl_t *cmdtp, int flag,
 
 	if (himport_r(&env_htab, ptr, size, sep, del ? 0 : H_NOCLEAR,
 			crlf_is_lf, 0, NULL) == 0) {
-		pr_err("Environment import failed: errno = %d\n", errno);
+		pr_err("## Error: Environment import failed: errno = %d\n",
+		       errno);
 		return 1;
 	}
 	gd->flags |= GD_FLG_ENV_READY;

env/common.c

@@ -79,7 +79,8 @@ void set_default_env(const char *s, int flags)
 	if (himport_r(&env_htab, (char *)default_environment,
 			sizeof(default_environment), '\0', flags, 0,
 			0, NULL) == 0)
-		pr_err("Environment import failed: errno = %d\n", errno);
+		pr_err("## Error: Environment import failed: errno = %d\n",
+		       errno);
 
 	gd->flags |= GD_FLG_ENV_READY;
 	gd->flags |= GD_FLG_ENV_DEFAULT;