[stable-8] Fix the homebrew module failing because of warnings (#8406) (#8429)

Fix the homebrew module failing because of warnings (#8406)

Instead of checking if there is an error message, which can also be a
warning, we now check the return code.

This commit fixes #8229 #7044

Co-authored-by: Strahinja Kustudic <strahinjak@nordeus.com>
(cherry picked from commit 43cb5a0d54)

Co-authored-by: Strahinja Kustudic <kustodian@gmail.com>

changelogs/fragments/8406-fix-homebrew-cask-warning.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+  - homebrew - do not fail when brew prints warnings (https://github.com/ansible-collections/community.general/pull/8406, https://github.com/ansible-collections/community.general/issues/7044).

plugins/modules/homebrew.py

@@ -488,9 +488,9 @@ class Homebrew(object):
             self.current_package,
         ]
         rc, out, err = self.module.run_command(cmd)
-        if err:
+        if rc != 0:
             self.failed = True
-            self.message = err.strip()
+            self.message = err.strip() or ("Unknown failure with exit code %d" % rc)
             raise HomebrewException(self.message)
         data = json.loads(out)