Fixed issue #1028: Labeling of Plot of target vs qsvt (#1029)

I have resolved the issue mentioned in
#1028 related to the tutorial
introduction to qsvt, which can be found at
https://github.com/PennyLaneAI/qml/blob/master/demonstrations/tutorial_intro_qsvt.py.

demonstrations/tutorial_intro_qsvt.py

@@ -122,8 +122,8 @@ def qsvt_output(a):
 target = [target_poly(a) for a in a_vals]
 
 
-plt.plot(a_vals, qsvt, label="target")
-plt.plot(a_vals, target, "*", label="qsvt")
+plt.plot(a_vals, target, label="target")
+plt.plot(a_vals, qsvt, "*", label="qsvt")
 
 plt.legend()
 plt.show()