Make mappages fit on the page

cf7b6702 · Austin Clements · 82bb0b56 · cf7b6702
--- a/vm.c
+++ b/vm.c
@@ -77,8 +77,7 @@ mappages(pde_t *pgdir, void *va, uint size, uint pa,
  a = (char *) PGROUNDDOWN((uint) va);
  last = (char *) PGROUNDDOWN(((uint) va) + size - 1);
  for(;;){
-    pte = walkpgdir(pgdir, a, alloc);
-    if(pte == 0)
+    if((pte = walkpgdir(pgdir, a, alloc) == 0)
      return -1;
    if(*pte & PTE_P)
      panic("remap");