Fix basic example, parameter mismatch between host and wasm

[hendradarwin]

Problem

When you build the host application located at samples\basic\src\main.c
build the wasm-app located at samples\basic\wasm-apps\testapp.c
and then run the host with wasm app

./basic -f wasm-app/testapp.wasm

you will get an error when calling float_to_string function:

call wasm function float_to_string failed. error: Exception: out of bounds memory access

In my case, I'm compiling the host on Windows, and compiling the wasm-app on Linux.

Solution

After taking a look at the argument array for calling the float_to_string function on the main.c file
I have noticed that the array assignment is not correct.

    argv2[1] = wasm_buffer; // the second argument is the wasm buffer address
    argv2[3] = 1000;         //  the third argument is the wasm buffer size
    argv2[4] = 3; //  the last argument is the digits after decimal point for
                  //  converting float to string

it is supposed to be

    argv2[1] = wasm_buffer; // the second argument is the wasm buffer address
    argv2[2] = 1000;         //  the third argument is the wasm buffer size
    argv2[3] = 3; //  the last argument is the digits after decimal point for
                  //  converting float to string

[TianlongLiang]

LGTM