[welcome] Drop unnecessary parameter

src/modules/welcome/WelcomeViewStep.cpp

@@ -135,5 +135,5 @@ WelcomeViewStep::setConfigurationMap( const QVariantMap& configurationMap )
 
 Calamares::RequirementsList WelcomeViewStep::checkRequirements()
 {
-    return m_requirementsChecker->checkRequirements( m_widget );
+    return m_requirementsChecker->checkRequirements();
 }

src/modules/welcome/checker/RequirementsChecker.cpp

@@ -60,9 +60,9 @@ RequirementsChecker::RequirementsChecker( QObject* parent )
 {
 }
 
-Calamares::RequirementsList RequirementsChecker::checkRequirements(QWidget* some_widget)
+Calamares::RequirementsList RequirementsChecker::checkRequirements()
 {
-    QSize availableSize = qApp->desktop()->availableGeometry( some_widget ).size();
+    QSize availableSize = qApp->desktop()->availableGeometry().size();
 
     bool enoughStorage = false;
     bool enoughRam = false;

src/modules/welcome/checker/RequirementsChecker.h

@@ -33,7 +33,7 @@ public:
 
     void setConfigurationMap( const QVariantMap& configurationMap );
 
-    Calamares::RequirementsList checkRequirements( QWidget* some_widget );
+    Calamares::RequirementsList checkRequirements();
 
 private:
     QStringList m_entriesToCheck;