change errno to error to avoid confusion

arch/x86_64/archctl.c

@@ -12,21 +12,21 @@ struct syscall_ret arch_archctl(uintptr_t op, uintptr_t arg) {
     switch (op) {
     case __ARCHCTL_SET_FSBASE:
         if (!arch_mem_addr_is_user(arg)) {
-            ret.errno = EINVAL;
+            ret.error = EINVAL;
             return ret;
         }
         asm_wrmsr(MSR_FS_BASE, arg);
         return ret;
     case __ARCHCTL_SET_GSBASE:
         if (!arch_mem_addr_is_user(arg)) {
-            ret.errno = EINVAL;
+            ret.error = EINVAL;
             return ret;
         }
         // Update the inactive GSBASE MSR, not ours.
         asm_wrmsr(MSR_KERNEL_GS_BASE, arg);
         return ret;
     default:
-        ret.errno = EINVAL;
+        ret.error = EINVAL;
         return ret;
     }
 }