Fix typos

Closes #1513

tests/test_helper.tcl

@@ -306,7 +306,7 @@ proc signal_idle_client fd {
     }
 }
 
-# The the_end funciton gets called when all the test units were already
+# The the_end function gets called when all the test units were already
 # executed, so the test finished.
 proc the_end {} {
     # TODO: print the status, exit with the rigth exit code.