Fix rustfmt

Author: Aaron1011

crates/backtrace-sys/build.rs

@@ -38,7 +38,9 @@ fn main() {
     // the less efficient `read`-based code.
     // Using `mmap` on macOS causes weird isseus - see
     // https://github.com/rust-lang/rust/pull/45866
-    if target.contains("windows")/* || target.contains("darwin")*/ {
+    if target.contains("windows")
+    /* || target.contains("darwin")*/
+    {
         build.file("src/libbacktrace/read.c");
     } else {
         build.file("src/libbacktrace/mmapio.c");