make fs/buffer.c:cont_expand_zero() static

cont_expand_zero() can become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/buffer.c

@@ -2211,7 +2211,7 @@ int generic_cont_expand_simple(struct inode *inode, loff_t size)
 	return err;
 }
 
-int cont_expand_zero(struct file *file, struct address_space *mapping,
+static int cont_expand_zero(struct file *file, struct address_space *mapping,
 			    loff_t pos, loff_t *bytes)
 {
 	struct inode *inode = mapping->host;