Add an optional "---fix" argument to format-checking script

.ci/clang-format.sh

@@ -3,6 +3,11 @@
 # SPDX-FileCopyrightText: 2023 Citra Emulator Project
 # SPDX-License-Identifier: GPL-2.0-or-later
 
+fix=false
+if [ "$1" == "--fix" ]; then
+    fix=true
+fi
+
 if grep -nrI '\s$' src *.yml *.txt *.md Doxyfile .gitignore .gitmodules .ci* dist/*.desktop \
                  dist/*.svg dist/*.xml; then
     echo Trailing whitespace found, aborting
@@ -25,12 +30,16 @@ fi
 set +x
 
 for f in $files_to_lint; do
+    if [ "$fix" = true ]; then
+        $CLANG_FORMAT -i "$f"
+    else
         d=$(diff -u "$f" <($CLANG_FORMAT "$f") || true)
         if ! [ -z "$d" ]; then
             echo "!!! $f not compliant to coding style, here is the fix:"
             echo "$d"
             fail=1
         fi
+    fi
 done
 
 set -x