Update run-make/issue-22131 to new rustdoc --test format

Author: GuillaumeGomez

src/test/run-make/issue-22131/Makefile

@@ -4,4 +4,4 @@ all: foo.rs
 	$(RUSTC) --cfg 'feature="bar"' --crate-type lib foo.rs
 	$(HOST_RPATH_ENV) '$(RUSTDOC)' --test --cfg 'feature="bar"' \
 		-L $(TMPDIR) foo.rs |\
-		grep -q 'test foo_0 ... ok'
+		grep -q 'foo.rs - line 11 ... ok'