fs/9p/vfs_file.c: use new return type vm_fault_t

Use new return type vm_fault_t for page_mkwrite handler.

See 1c8f422 ("mm: change return type to vm_fault_t") for reference.

Link: http://lkml.kernel.org/r/20180702154928.GA3964@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <[email protected]>
Reviewed-by: Matthew Wilcox <[email protected]>
Acked-by: Jun Piao <[email protected]>
Cc: Eric Van Hensbergen <[email protected]>
Cc: Ron Minnich <[email protected]>
Cc: Latchesar Ionkov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Dominique Martinet <[email protected]>

fs/9p/vfs_file.c

@@ -533,7 +533,7 @@ v9fs_mmap_file_mmap(struct file *filp, struct vm_area_struct *vma)
 	return retval;
 }
 
-static int
+static vm_fault_t
 v9fs_vm_page_mkwrite(struct vm_fault *vmf)
 {
 	struct v9fs_inode *v9inode;