Fix Create Disk Image Example

[AlexJMohr]

The example code didn't compile. This patch fixes that.

Let me know if it needs any changes, and thanks for making this awesome crate!

[phil-opp]

Thanks a lot! Looks like I forgot to try this snippet.

One minor nit: I think the Path::new call is simple enough to do apply it in the out_dir/kernel bindings directly instead of introducing new out_dir_path/kernel_path bindings. I left some suggestions below for this.

[AlexJMohr]

@phil-opp I agree, that looks simpler.

EDIT: now I remember why I did it that way. The compiler complains about temporary value is freed at the end of this statement

error[E0716]: temporary value dropped while borrowed
  --> build.rs:8:29
   |
8  |     let kernel = Path::new(&std::env::var_os("CARGO_BIN_FILE_KERNEL_kernel").unwrap());
   |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - temporary value is freed at the end of this statement
   |                             |
   |                             creates a temporary value which is freed while still in use
...
18 |     bootloader::BiosBoot::new(&kernel)
   |                               ------- borrow later used here
   |
help: consider using a `let` binding to create a longer lived value
   |
8  ~     let binding = std::env::var_os("CARGO_BIN_FILE_KERNEL_kernel").unwrap();
9  ~     let kernel = Path::new(&binding);
   |

If you have a different way, let me know

[asensio-project]

Hello, I think that in the Cargo.toml file you should change ovmf_prebuilt to ovmf-prebuilt because the first package doesn't exists in crates.io but the second does.

[phil-opp]

The compiler complains about temporary value is freed at the end of this statement

I think we can use PathBuf instead of Path to take ownership of the string. I pushed 63284c6 with that change.

Hello, I think that in the Cargo.toml file you should change ovmf_prebuilt to ovmf-prebuilt because the first package doesn't exists in crates.io but the second does.

Thanks, done in 0d24cef.

[phil-opp]

Could you try whether the new version works for you? Then we can finally merge this!

[asensio-project]

The new version is working very good, thanks!

[phil-opp]

Ok great, thanks for testing!