env: Fix warning when forcing environment without ENV_ACCESS_IGNORE_FORCE

Since commit 0f036bf4 ("env: Warn on force access if ENV_ACCESS_IGNORE_FORCE set")
a warning message is displayed when setenv -f is used WITHOUT
CONFIG_ENV_ACCESS_IGNORE_FORCE, but the variable is set anyway, resulting
in lots of log pollution.

env_flags_validate() returns 0 if the access is accepted, or non zero
if it is refused.

So the original code
	#ifndef CONFIG_ENV_ACCESS_IGNORE_FORCE
		if (flag & H_FORCE)
			return 0;
	#endif

was correct, it returns 0 (accepts the modification) if forced UNLESS
IGNORE_FORCE is set (in which case access checks in the following code
are applied). The broken patch just added a printf to the force accepted
case.

To obtain the intent of the patch we need this:
	if (flag & H_FORCE) {
	#ifdef CONFIG_ENV_ACCESS_IGNORE_FORCE
		printf("## Error: Can't force access to \"%s\"\n", name);
	#else
		return 0;
	#endif
	}

Fixes: 0f036bf4 ("env: Warn on force access if ENV_ACCESS_IGNORE_FORCE set")

Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group>