rust: optimize rust symbol generation for SeqFile

From: Kunwu Chan <[email protected]>

When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64 with ARCH=arm64, the following symbols are generated:

$nm vmlinux | grep ' _R'.*SeqFile | rustfilt ffff8000805b78ac T <kernel::seq_file::SeqFile>::call_printf

This Rust symbol is trivial wrappers around the C functions seq_printf. It doesn't make sense to go through a trivial wrapper for its functions, so mark it inline.

After doing so, the above symbol will not in output.

---
 rust/kernel/seq_file.rs | 1 +
 1 file changed, 1 insertion(+)

index 04947c672979..efc4dd09850a 100644
@@ -30,6 +30,7 @@ pub unsafe fn from_raw<'a>(ptr: *mut bindings::seq_file) -> &'a SeqFile {
     }
 
     /// Used by the [`seq_print`] macro.
+    #[inline]
     pub fn call_printf(&self, args: core::fmt::Arguments<'_>) {
         // SAFETY: Passing a void pointer to `Arguments` is valid for `%pA`.
         unsafe {

2.43.0