Use `_SRCS` and not `_SOURCES`, the latter of which makes automake assume
there's something for it to do.
Closes: #749
Approved by: jlebon
if ENABLE_RUST
bupsplitpath = @abs_top_builddir@/target/@RUST_TARGET_SUBDIR@/libbupsplit_rs.a
-BUPSPLIT_RUST_SOURCES = rust/src/bupsplit.rs
-EXTRA_DIST += $(BUPSPLIT_RUST_SOURCES)
-$(bupsplitpath): Makefile $(BUPSPLIT_RUST_SOURCES)
+BUPSPLIT_RUST_SRCS = rust/src/bupsplit.rs
+EXTRA_DIST += $(BUPSPLIT_RUST_SRCS)
+$(bupsplitpath): Makefile $(BUPSPLIT_RUST_SRCS)
cd $(top_srcdir)/rust && CARGO_TARGET_DIR=@abs_top_builddir@/target cargo build --verbose $(CARGO_RELEASE_ARGS)
else
bupsplitpath = libbupsplit.la