Respect ro.boot.fstab_suffix in swapon_all

While mount_all and umount_all were updated to use ro.boot.fstab_suffix,
I neglected to update swapon_all. Trivially copied from umount_all.

Bug: 142424832
Change-Id: Icd706fe7a1fe16c687cd2811b0a3158d7d2e224e
diff --git a/init/check_builtins.cpp b/init/check_builtins.cpp
index 450c079..481fa31 100644
--- a/init/check_builtins.cpp
+++ b/init/check_builtins.cpp
@@ -202,6 +202,14 @@
     return {};
 }
 
+Result<void> check_swapon_all(const BuiltinArguments& args) {
+    auto options = ParseSwaponAll(args.args);
+    if (!options.ok()) {
+        return options.error();
+    }
+    return {};
+}
+
 Result<void> check_sysclktz(const BuiltinArguments& args) {
     ReturnIfAnyArgsEmpty();