[fractal] ci: Fix pre-commit hook

[Kévin Commaille <kcommaille src gnome org>]

commit 808f4b5a2654f0f1bcc861decbd7bd97585921d9
Author: Kévin Commaille <zecakeh tedomum fr>
Date:   Sat May 21 10:32:25 2022 +0200

    ci: Fix pre-commit hook
    
    Because rustfmt isn't aware of the cargo manifest, it would complain that
    we use async methods with the rust 2015 version.

 scripts/checks.sh | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/scripts/checks.sh b/scripts/checks.sh
index 0cf92b6a3..0e7ccabea 100755
--- a/scripts/checks.sh
+++ b/scripts/checks.sh
@@ -210,8 +210,7 @@ run_rustfmt() {
         staged_files=`git diff --name-only --cached | grep '.rs$'`
         result=0
         for file in ${staged_files[@]}; do
-
-            if ! rustfmt --unstable-features --skip-children --check $file; then
+            if ! cargo +nightly fmt -- --unstable-features --skip-children --check $file; then
                 result=1
             fi
         done