BUG_ON() Conversion in fs/ext2/

this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index b3dbd71..0165388 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -416,8 +416,7 @@
 
 	lock_page(page);
 	err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
-	if (err)
-		BUG();
+	BUG_ON(err);
 	de->inode = cpu_to_le32(inode->i_ino);
 	ext2_set_de_type (de, inode);
 	err = ext2_commit_chunk(page, from, to);
@@ -554,8 +553,7 @@
 		from = (char*)pde - (char*)page_address(page);
 	lock_page(page);
 	err = mapping->a_ops->prepare_write(NULL, page, from, to);
-	if (err)
-		BUG();
+	BUG_ON(err);
 	if (pde)
 		pde->rec_len = cpu_to_le16(to-from);
 	dir->inode = 0;