NFS: Switch from intr mount option to TASK_KILLABLE

By using the TASK_KILLABLE infrastructure, we can get rid of the 'intr'
mount option.  We have to use _killable everywhere instead of _interruptible
as we get rid of rpc_clnt_sigmask/sigunmask.

Signed-off-by: Liam R. Howlett <howlett@gmail.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 51cc1bd..60e3e87 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -490,7 +490,7 @@
 /*
  * Wait for a request to complete.
  *
- * Interruptible by signals only if mounted with intr flag.
+ * Interruptible by fatal signals only.
  */
 static int nfs_wait_on_requests_locked(struct inode *inode, pgoff_t idx_start, unsigned int npages)
 {
@@ -816,12 +816,7 @@
 
 static void nfs_execute_write(struct nfs_write_data *data)
 {
-	struct rpc_clnt *clnt = NFS_CLIENT(data->inode);
-	sigset_t oldset;
-
-	rpc_clnt_sigmask(clnt, &oldset);
 	rpc_execute(&data->task);
-	rpc_clnt_sigunmask(clnt, &oldset);
 }
 
 /*