[tutorials] Don't successfully exit tutorials if input files are missing

This doesn't help the user, and also confuses the CI when testing,
because tutorials can apparently succeed even if they do nothing.

Author: guitargeek

tutorials/hist/hist015_TH1_read_and_draw.py

@@ -22,14 +22,10 @@
 pad2.Draw()
 pad3.Draw()
 #
-# We connect the ROOT file generated in a previous tutorial
+# We connect the ROOT file generated in the hsimple.py tutorial
 #
-File = "py-hsimple.root"
-if (ROOT.gSystem.AccessPathName(File)) :
-    ROOT.Info("hist015_TH1_read_and_draw.py", File+" does not exist")
-    exit()
 
-example = TFile(File)
+example = TFile("py-hsimple.root")
 example.ls()
 
 # Draw a global picture title
@@ -86,4 +82,4 @@
 c1.Update()
 
 if (example.IsOpen()):
-    example.Close()
+    example.Close()

tutorials/hist/hist015_TH1_read_and_draw_uhi.py

@@ -19,13 +19,9 @@
 mpl_fig = plt.figure(figsize=(14, 12))
 gs = mpl_fig.add_gridspec(3, 2, height_ratios=[1.5, 1.5, 1.5])
 
-# We connect the ROOT file generated in a previous tutorial
-File = "py-hsimple.root"
-if ROOT.gSystem.AccessPathName(File):
-    ROOT.Info("hist015_TH1_read_and_draw.py", File + " does not exist")
-    exit()
+# We connect the ROOT file generated in the hsimple.py tutorial
 
-example = TFile(File)
+example = TFile("py-hsimple.root")
 example.ls()
 
 # Draw histogram hpx in first pad.