test: Fix linter issues

These are some linter issues that were found in a new version of the
linter. Let's fix them now before that linter hits our test suite.

examples/lib/exec-send-recv.go

@@ -232,10 +232,7 @@ func Run() error {
 		}
 	}()
 
-	if err := obj.Run(); err != nil {
+	return obj.Run()
-		return err
-	}
-	return nil
 }
 
 func main() {

examples/lib/libmgmt-subgraph0.go

@@ -239,10 +239,7 @@ func Run() error {
 		}
 	}()
 
-	if err := obj.Run(); err != nil {
+	return obj.Run()
-		return err
-	}
-	return nil
 }
 
 func main() {

examples/lib/libmgmt-subgraph1.go

@@ -229,10 +229,7 @@ func Run() error {
 		}
 	}()
 
-	if err := obj.Run(); err != nil {
+	return obj.Run()
-		return err
-	}
-	return nil
 }
 
 func main() {

examples/lib/libmgmt1.go

@@ -190,10 +190,7 @@ func Run() error {
 		}
 	}()
 
-	if err := obj.Run(); err != nil {
+	return obj.Run()
-		return err
-	}
-	return nil
 }
 
 func main() {

examples/lib/libmgmt2.go

@@ -184,10 +184,7 @@ func Run(count uint) error {
 		}
 	}()
 
-	if err := obj.Run(); err != nil {
+	return obj.Run()
-		return err
-	}
-	return nil
 }
 
 func main() {

examples/lib/libmgmt3.go

@@ -234,10 +234,7 @@ func Run() error {
 		}
 	}()
 
-	if err := obj.Run(); err != nil {
+	return obj.Run()
-		return err
-	}
-	return nil
 }
 
 func main() {

test/shell/libmgmt-change1.go

@@ -167,10 +167,7 @@ func Run() error {
 		}
 	}()
 
-	if err := obj.Run(); err != nil {
+	return obj.Run()
-		return err
-	}
-	return nil
 }
 
 func main() {

test/shell/libmgmt-change2.go

@@ -180,10 +180,7 @@ func Run() error {
 		}
 	}()
 
-	if err := obj.Run(); err != nil {
+	return obj.Run()
-		return err
-	}
-	return nil
 }
 
 func main() {