kbuild: rust: rename flag to -Zdebuginfo-for-profiling for Rust >= 1.98

Starting with Rust 1.98.0 (expected 2026-08-20), the
`-Zdebug-info-for-profiling` flag has been renamed to
`-Zdebuginfo-for-profiling` (i.e. one less dash, to match `debuginfo`s
in other flags) [1].

Without this change, one gets in the latest nightlies:

    error: unknown unstable option: `debug-info-for-profiling`

Thus pass the right name.

Link: rust-lang/rust#156887 [1]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260602151638.14358-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: ojeda

scripts/Makefile.autofdo

@@ -3,7 +3,7 @@
 # Enable available and selected Clang AutoFDO features.
 
 CFLAGS_AUTOFDO_CLANG := -fdebug-info-for-profiling -mllvm -enable-fs-discriminator=true -mllvm -improved-fs-discriminator=true
-RUSTFLAGS_AUTOFDO_CLANG := -Zdebug-info-for-profiling -Cllvm-args=-enable-fs-discriminator=true -Cllvm-args=-improved-fs-discriminator=true
+RUSTFLAGS_AUTOFDO_CLANG := $(if $(call rustc-min-version,109800),-Zdebuginfo-for-profiling,-Zdebug-info-for-profiling) -Cllvm-args=-enable-fs-discriminator=true -Cllvm-args=-improved-fs-discriminator=true
 
 ifndef CONFIG_DEBUG_INFO
   CFLAGS_AUTOFDO_CLANG += -gmlt