[SPARC32]: Copy full soft PMD in vmalloc fault handler.

sparc_do_fault assumes that pmd_val(*pmd) = pmd_val(*pmd_k) will
duplicate a PMD entry.  With large soft-PMDs this doesn't work.

arch/sparc/mm/fault.c

@@ -392,7 +392,7 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
 
 		if (pmd_present(*pmd) || !pmd_present(*pmd_k))
 			goto bad_area_nosemaphore;
-		pmd_val(*pmd) = pmd_val(*pmd_k);
+		*pmd = *pmd_k;
 		return;
 	}
 }