run zig fmt on some of the codebase

See #1003

std/debug/failing_allocator.zig

@@ -13,14 +13,14 @@ pub const FailingAllocator = struct {
     deallocations: usize,
 
     pub fn init(allocator: &mem.Allocator, fail_index: usize) FailingAllocator {
-        return FailingAllocator {
+        return FailingAllocator{
             .internal_allocator = allocator,
             .fail_index = fail_index,
             .index = 0,
             .allocated_bytes = 0,
             .freed_bytes = 0,
             .deallocations = 0,
-            .allocator = mem.Allocator {
+            .allocator = mem.Allocator{
                 .allocFn = alloc,
                 .reallocFn = realloc,
                 .freeFn = free,