Repair a bad translation of the exec statement.
Fixes #1038: pdb command line invocation fails.
diff --git a/Lib/pdb.py b/Lib/pdb.py
index 8a52778..3d79b4d 100755
--- a/Lib/pdb.py
+++ b/Lib/pdb.py
@@ -1166,12 +1166,8 @@
         self._wait_for_mainpyfile = 1
         self.mainpyfile = self.canonic(filename)
         self._user_requested_quit = 0
-        fp = open(filename)
-        try:
-            script = fp.read()
-        finally:
-            fp.close()
-        statement = 'exec("%s")' % script
+        with open(filename) as fp:
+            statement = fp.read()
         self.run(statement)
 
 # Simplified interface