BUG_ON() Conversion in fs/smbfs/

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/smbfs/file.c b/fs/smbfs/file.c
index c56bd99..ed9a24d 100644
--- a/fs/smbfs/file.c
+++ b/fs/smbfs/file.c
@@ -178,11 +178,9 @@
 	unsigned offset = PAGE_CACHE_SIZE;
 	int err;
 
-	if (!mapping)
-		BUG();
+	BUG_ON(!mapping);
 	inode = mapping->host;
-	if (!inode)
-		BUG();
+	BUG_ON(!inode);
 
 	end_index = inode->i_size >> PAGE_CACHE_SHIFT;