Remove --recursive from git submodule update

Author: John Nonweiler

COMPILING.md

@@ -242,7 +242,7 @@ require manual modification of build files.
    first.
 3. Update git submodules:
    ```
-   git submodule update --init --recursive
+   git submodule update --init
    ```
 4. Generate build files with CMake:
    ```

jbmc/src/Makefile

@@ -55,7 +55,7 @@ dist_clean:
 	rm -rf $(ROOT)dist
 
 setup-submodules:
-	git submodule update --init --recursive
+	git submodule update --init
 
 .PHONY: dist
 dist: setup-submodules all