fs/ext2: use BUG_ON

if (...) BUG(); should be replaced with BUG_ON(...) when the test has no
side-effects to allow a definition of BUG_ON that drops the code completely.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@ disable unlikely @ expression E,f; @@

(
  if (<... f(...) ...>) { BUG(); }
|
- if (unlikely(E)) { BUG(); }
+ BUG_ON(E);
)

@@ expression E,f; @@

(
  if (<... f(...) ...>) { BUG(); }
|
- if (E) { BUG(); }
+ BUG_ON(E);
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index a0995eb..dd9dbb2 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -41,8 +41,8 @@
 {
 	if (len == (1 << 16))
 		return cpu_to_le16(EXT2_MAX_REC_LEN);
-	else if (len > (1 << 16))
-		BUG();
+	else
+		BUG_ON(len > (1 << 16));
 	return cpu_to_le16(len);
 }