ci: Disable the check for >1 s! invocation

Apparently we already violate this in a few places, it just doesn't show
up because whitespace doesn't line up with what we expect (lack of
formatting). Just disable it for now so we can format the files.

(backport <rust-lang#4107>)
(cherry picked from commit 0189456)

ci/style.rs

@@ -97,7 +97,10 @@ enum State {
 
 fn check_style(file: &str, path: &Path, err: &mut Errors) {
     let mut state = State::Start;
-    let mut s_macros = 0;
+
+    // FIXME: see below
+    // let mut s_macros = 0;
+
     let mut f_macros = 0;
     let mut in_impl = false;
 
@@ -140,7 +143,8 @@ fn check_style(file: &str, path: &Path, err: &mut Errors) {
         } else if line.starts_with("type ") && !in_impl {
             State::Typedefs
         } else if line.starts_with("s! {") {
-            s_macros += 1;
+            // FIXME: see below
+            // s_macros += 1;
             State::Structs
         } else if line.starts_with("s_no_extra_traits! {") {
             // multiple macros of this type are allowed
@@ -175,10 +179,13 @@ fn check_style(file: &str, path: &Path, err: &mut Errors) {
             f_macros += 1;
             err.error(path, i, "multiple f! macros in one module");
         }
-        if s_macros == 2 {
-            s_macros += 1;
-            err.error(path, i, "multiple s! macros in one module");
-        }
+
+        // FIXME(#4109): multiple should be allowed if at least one is `cfg(not) within `cfg_if`.
+        // For now just disable this and check by hand.
+        // if s_macros == 2 {
+        //     s_macros += 1;
+        //     err.error(path, i, "multiple s! macros in one module");
+        // }
 
         state = line_state;
     }