scripts: sphinx-pre-install: fix venv version check logic

The logic which checks if the venv version is good enough
but was not activated is broken: it is checking against
the wrong val, making it to recommend to re-create a venv
every time. Fix it.
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/afe01b7863fd655986d84ace8948f3d7aede796d.1656756450.git.mchehab@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net>

scripts/sphinx-pre-install

@@ -741,7 +741,7 @@ sub recommend_sphinx_upgrade()
 
 	# Get the highest version from sphinx_*/bin/sphinx-build and the
 	# corresponding command to activate the venv/virtenv
-	$activate_cmd = get_virtenv();
+	($activate_cmd, $venv_ver) = get_virtenv();
 
 	# Store the highest version from Sphinx existing virtualenvs
 	if (($activate_cmd ne "") && ($venv_ver gt $cur_version)) {
@@ -759,10 +759,14 @@ sub recommend_sphinx_upgrade()
 	# Either there are already a virtual env or a new one should be created
 	$need_pip = 1;
 
+	return if (!$latest_avail_ver);
+
 	# Return if the reason is due to an upgrade or not
 	if ($latest_avail_ver lt $rec_version) {
 		$rec_sphinx_upgrade = 1;
 	}
+
+	return $latest_avail_ver;
 }
 
 #
@@ -820,7 +824,7 @@ sub recommend_sphinx_version($)
 	}
 
 	# Suggest newer versions if current ones are too old
-	if ($latest_avail_ver && $cur_version ge $min_version) {
+	if ($latest_avail_ver && $latest_avail_ver ge $min_version) {
 		# If there's a good enough version, ask the user to enable it
 		if ($latest_avail_ver ge $rec_version) {
 			printf "\nNeed to activate Sphinx (version $latest_avail_ver) on virtualenv with:\n";
@@ -897,7 +901,7 @@ sub check_needs()
 		}
 	}
 
-	recommend_sphinx_upgrade();
+	my $venv_ver = recommend_sphinx_upgrade();
 
 	my $virtualenv_cmd;