rust: kbuild: remove unused variable

Since we are adding one more proc macro crate (`zerocopy-derive`),
we are refactoring their handling.

`libpin_init_internal_extension` was added to mimic the setup for
`macros`, but it is not used, since the extension is expected to be
the same.

Thus remove it.

Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20260608141439.182634-4-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

diff --git a/rust/Makefile b/rust/Makefile
index bec9726f256ce99677c78827bbb36ed1d01e1134..2b4a3983bb1e38b4d4537a2b26843e79dd0440a7 100644 (file)
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -51,7 +51,6 @@ libmacros_name := $(shell MAKEFLAGS= $(RUSTC) --print file-names --crate-name ma
 libmacros_extension := $(patsubst libmacros.%,%,$(libmacros_name))
 
 libpin_init_internal_name := $(shell MAKEFLAGS= $(RUSTC) --print file-names --crate-name pin_init_internal --crate-type proc-macro - </dev/null)
-libpin_init_internal_extension := $(patsubst libpin_init_internal.%,%,$(libpin_init_internal_name))
 
 always-$(CONFIG_RUST) += $(libmacros_name) $(libpin_init_internal_name)