remount: Remove unused option -C/--clean_scratch_files

The option was added for debugging purposes in case the "test argv[0] ==
clean_scratch_files" method breaks.
Now it has no user at all and no reason to maintain it, so just remove it.

Also don't use MyLogger() when running as clean_scratch_files, as
clean_scratch_files don't have stdout/stderr.

Bug: 241179247
Test: Presubmit
Change-Id: I2d8069f59fe6b85fc84ab07bb2df6efb39d6ecaa
diff --git a/fs_mgr/fs_mgr_remount.cpp b/fs_mgr/fs_mgr_remount.cpp
index 01517b0..4a927d0 100644
--- a/fs_mgr/fs_mgr_remount.cpp
+++ b/fs_mgr/fs_mgr_remount.cpp
@@ -475,17 +475,16 @@
     return retval;
 }
 
-static int do_clean_scratch_files() {
-    android::fs_mgr::CleanupOldScratchFiles();
-    return 0;
-}
-
 int main(int argc, char* argv[]) {
-    android::base::InitLogging(argv, MyLogger);
+    // Do not use MyLogger() when running as clean_scratch_files, as stdout/stderr of daemon process
+    // are discarded.
     if (argc > 0 && android::base::Basename(argv[0]) == "clean_scratch_files"s) {
-        return do_clean_scratch_files();
+        android::fs_mgr::CleanupOldScratchFiles();
+        return 0;
     }
 
+    android::base::InitLogging(argv, MyLogger);
+
     // Make sure we are root.
     if (::getuid() != 0) {
         LOG(ERROR) << "Not running as root. Try \"adb root\" first.";
@@ -509,7 +508,6 @@
             {"help", no_argument, nullptr, 'h'},
             {"reboot", no_argument, nullptr, 'R'},
             {"verbose", no_argument, nullptr, 'v'},
-            {"clean_scratch_files", no_argument, nullptr, 'C'},
             {0, 0, nullptr, 0},
     };
     for (int opt; (opt = ::getopt_long(argc, argv, "hRT:v", longopts, nullptr)) != -1;) {
@@ -530,8 +528,6 @@
             case 'v':
                 verbose = true;
                 break;
-            case 'C':
-                return do_clean_scratch_files();
             default:
                 LOG(ERROR) << "Bad Argument -" << char(opt);
                 usage(BADARG);