minor style fixes

src/os/mod.rs

@@ -36,9 +36,10 @@ impl Stack {
       Stack { ptr: ptr as *mut u8, len: len }
     };
 
-    try!(unsafe {
-      if sys::protect_stack(stack.ptr) { Ok(()) }
-      else { Err(IoError::last_os_error()) }
+    try!(if unsafe { sys::protect_stack(stack.ptr) } {
+      Ok(())
+    } else {
+      Err(IoError::last_os_error())
     });
 
     Ok(stack)

src/os/sys/unix.rs

@@ -32,11 +32,10 @@ const STACK_FLAGS: c_int = libc::MAP_PRIVATE
 pub unsafe fn map_stack(len: usize) -> Option<*mut u8> {
   let ptr = mmap(ptr::null_mut(), len as size_t,
                  STACK_PROT, STACK_FLAGS, -1, 0);
-  if ptr != MAP_FAILED {
-    Some(ptr as *mut u8)
-  }
-  else {
+  if ptr == MAP_FAILED {
     None
+  } else {
+    Some(ptr as *mut u8)
   }
 }