lint: update format-code script

Due to openbmc/openbmc-build-scripts@55448ad, format-code scripts are
now required to have a #!.  Add one here.

Format-code scripts are also ran from an arbitrary directory but the
path to the root of the repository is passed as the first argument.
Switch to that directory so `npm` does the right thing.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ic15ef0af7d7ebd224762e9eaba41d3b92ce5e5bd
diff --git a/format-code.sh b/format-code.sh
index b490dd2..9649a40 100755
--- a/format-code.sh
+++ b/format-code.sh
@@ -1,3 +1,4 @@
+#!/bin/bash
 # Run GUI Linting and Formatting as part of the CI Build process
 #
 # This is a short term solution. The long term solution to will be to
@@ -6,6 +7,13 @@
 
 set -e
 
+# When called from openbmc-build-scripts, the `pwd` could be anywhere, but
+# the root of the repo is passed in the first argument.  Switch to the repo
+# root so npm/git run in the right place.
+if [ -n "$1" ]; then
+    cd "$1"
+fi
+
 npm ci
 npm run lint
-git --no-pager diff --exit-code
\ No newline at end of file
+git --no-pager diff --exit-code