systemctl/core: ignore masked units in preset-all

With any masked unit that would that would be enabled by presets, we'd get:

test@rawhide $ sudo systemctl preset-all
Failed to execute operation: Unit file is masked.

test@rawhide $ sudo systemctl --root=/ preset-all
Operation failed: Cannot send after transport endpoint shutdown

Simply ignore those units:

test@rawhide $ sudo systemctl preset-all
Unit xxx.service is masked, ignoring.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/shared/install.c b/src/shared/install.c
index 35d83dd16c..74de8141f1 100644
--- a/src/shared/install.c
+++ b/src/shared/install.c
@@ -2539,6 +2539,9 @@ int unit_file_preset_all(
                                 continue;
 
                         r = preset_prepare_one(scope, &plus, &minus, &paths, mode, de->d_name);
+                        if (r == -ERFKILL)
+                                r = unit_file_changes_add(changes, n_changes,
+                                                          UNIT_FILE_IS_MASKED, de->d_name, NULL);
                         if (r < 0)
                                 return r;
                 }
@@ -2652,6 +2655,7 @@ DEFINE_STRING_TABLE_LOOKUP(unit_file_state, UnitFileState);
 static const char* const unit_file_change_type_table[_UNIT_FILE_CHANGE_TYPE_MAX] = {
         [UNIT_FILE_SYMLINK] = "symlink",
         [UNIT_FILE_UNLINK] = "unlink",
+        [UNIT_FILE_IS_MASKED] = "masked",
 };
 
 DEFINE_STRING_TABLE_LOOKUP(unit_file_change_type, UnitFileChangeType);