remove 'mkdir' from Main, that was a bad idea

Makefile.in

@@ -191,6 +191,7 @@ bin/manager.byte: $(MANAGER_CMO)
 ##############
 
 test: bin/why.byte  $(TOOLS)
+	mkdir -p output_why3
 	ocamlrun -bt bin/why.byte -I theories/ -D drivers/why3.drv \
 		-o output_why3 src/test.why
 	bin/why.byte -D drivers/alt_ergo.drv -I theories/ \
@@ -202,6 +203,7 @@ test: bin/why.byte  $(TOOLS)
 	echo bin/why.byte -D drivers/alt_ergo.drv -I theories/ \
 		--timeout 1 --prove theories/real.why 
 	@printf "*** Checking Coq file generation ***\\n"
+	@mkdir -p output_coq
 	@for i in int.Abs int.EuclideanDivision int.ComputerDivision  \
 		real.Abs real.FromIntTest real.SquareTest \
 		real.ExpLogTest real.PowerTest real.TrigonometryTest \

src/main.ml

@@ -206,8 +206,6 @@ let do_task env drv fname tname th task =
     | None ->
         printf "@[%a@]@?" (Driver.print_task drv) task
     | Some dir ->
-        try Unix.mkdir dir 0o755
-        with Unix.Unix_error (Unix.EEXIST,_,_) -> ();
         let file =
           let file = Filename.basename fname in
           try Filename.chop_extension file