Change r1 in four_arg_syscall to a u32.
I mistakenly kept it as a `usize` in my previous commit because memop passes pointers using r1, but four_arg_syscall is not used to call memop. Therefore the second argument can always be a u32.
diff --git a/core/platform/src/raw_syscalls.rs b/core/platform/src/raw_syscalls.rs
index 1743e3f..36ea454 100644
--- a/core/platform/src/raw_syscalls.rs
+++ b/core/platform/src/raw_syscalls.rs
@@ -116,7 +116,7 @@
/// depending on the system call class.
unsafe fn four_arg_syscall(
r0: u32,
- r1: usize,
+ r1: u32,
r2: usize,
r3: usize,
class: u8,
