rust: helpers: sort includes alphabetically in rust/helpers.c

Sort the #include directives of rust/helpers.c alphabetically and add a
comment specifying this. The reason for this is to improve readability
and to be consistent with the other files with a similar approach within
'rust/'.

Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: #1003
Signed-off-by: Ariel Miculas <amiculas@cisco.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230426204923.16195-1-amiculas@cisco.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: ariel-miculas

rust/helpers.c

@@ -16,16 +16,18 @@
  *
  * All symbols are exported as GPL-only to guarantee no GPL-only feature is
  * accidentally exposed.
+ *
+ * Sorted alphabetically.
  */
 
 #include <linux/bug.h>
 #include <linux/build_bug.h>
 #include <linux/err.h>
 #include <linux/errname.h>
-#include <linux/refcount.h>
 #include <linux/mutex.h>
-#include <linux/spinlock.h>
+#include <linux/refcount.h>
 #include <linux/sched/signal.h>
+#include <linux/spinlock.h>
 #include <linux/wait.h>
 
 __noreturn void rust_helper_BUG(void)