9452 ptable_dcmd() needs a little cleanup

*** 833,843 ****
          uintptr_t base;
          int h;
          int entry;
          uintptr_t pagesize;
          x86pte_t pte;
-         x86pte_t buf;
          physaddr_t paddr;
          size_t len;
  
          /*
           * The hats are kept in a list with khat at the head.
--- 833,842 ----
*** 897,911 ****
                  pagesize = mmu.level_size[level];
          }
  
          paddr = mmu_ptob((physaddr_t)pfn);
          for (entry = 0; entry < mmu.ptes_per_table; ++entry) {
!                 len = mdb_pread(&buf, mmu.pte_size,
                      paddr + entry * mmu.pte_size);
                  if (len != mmu.pte_size)
                          return (DCMD_ERR);
-                         pte = buf;
  
                  if (pte == 0)
                          continue;
  
                  mdb_printf("[%3d] va=0x%p ", entry,
--- 896,909 ----
                  pagesize = mmu.level_size[level];
          }
  
          paddr = mmu_ptob((physaddr_t)pfn);
          for (entry = 0; entry < mmu.ptes_per_table; ++entry) {
!                 len = mdb_pread(&pte, mmu.pte_size,
                      paddr + entry * mmu.pte_size);
                  if (len != mmu.pte_size)
                          return (DCMD_ERR);
  
                  if (pte == 0)
                          continue;
  
                  mdb_printf("[%3d] va=0x%p ", entry,