MIPS: Use BUG_ON() where possible.

Based on original patch by Stoyan Gaydarov <stoyboyker@gmail.com> which
missed a few places.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mm/ioremap.c b/arch/mips/mm/ioremap.c
index 59945b9..0c43248 100644
--- a/arch/mips/mm/ioremap.c
+++ b/arch/mips/mm/ioremap.c
@@ -27,8 +27,7 @@
 	end = address + size;
 	if (end > PMD_SIZE)
 		end = PMD_SIZE;
-	if (address >= end)
-		BUG();
+	BUG_ON(address >= end);
 	pfn = phys_addr >> PAGE_SHIFT;
 	do {
 		if (!pte_none(*pte)) {
@@ -52,8 +51,7 @@
 	if (end > PGDIR_SIZE)
 		end = PGDIR_SIZE;
 	phys_addr -= address;
-	if (address >= end)
-		BUG();
+	BUG_ON(address >= end);
 	do {
 		pte_t * pte = pte_alloc_kernel(pmd, address);
 		if (!pte)
@@ -75,8 +73,7 @@
 	phys_addr -= address;
 	dir = pgd_offset(&init_mm, address);
 	flush_cache_all();
-	if (address >= end)
-		BUG();
+	BUG_ON(address >= end);
 	do {
 		pud_t *pud;
 		pmd_t *pmd;