powerpc/mm: Fix infinite loop in hash fault with 4K page size

This is the same bug we fixed as part of 09567e7f
("powerpc/mm: Check paca psize is up to date for huge mappings"). Please
check that for details. The difference here is that faults were
happening on a 4K page at an address previously mapped by hugetlb.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/hash_utils_64.c

@@ -1148,9 +1148,10 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
 		}
 	}
 
+#endif /* CONFIG_PPC_64K_PAGES */
+
 	if (current->mm == mm)
 		check_paca_psize(ea, mm, psize, user_region);
-#endif /* CONFIG_PPC_64K_PAGES */
 
 #ifdef CONFIG_PPC_64K_PAGES
 	if (psize == MMU_PAGE_64K)