sendfile: remove .sendfile from filesystems that use generic_file_sendfile()

They can use generic_file_splice_read() instead. Since sys_sendfile() now
prefers that, there should be no change in behaviour.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 7c04752..8b0cbf4 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -616,7 +616,7 @@
 	.fsync = cifs_fsync,
 	.flush = cifs_flush,
 	.mmap  = cifs_file_mmap,
-	.sendfile = generic_file_sendfile,
+	.splice_read = generic_file_splice_read,
 	.llseek = cifs_llseek,
 #ifdef CONFIG_CIFS_POSIX
 	.ioctl	= cifs_ioctl,
@@ -637,7 +637,7 @@
 	.lock = cifs_lock,
 	.fsync = cifs_fsync,
 	.flush = cifs_flush,
-	.sendfile = generic_file_sendfile, /* BB removeme BB */
+	.splice_read = generic_file_splice_read,
 #ifdef CONFIG_CIFS_POSIX
 	.ioctl  = cifs_ioctl,
 #endif /* CONFIG_CIFS_POSIX */
@@ -656,7 +656,7 @@
 	.fsync = cifs_fsync,
 	.flush = cifs_flush,
 	.mmap  = cifs_file_mmap,
-	.sendfile = generic_file_sendfile,
+	.splice_read = generic_file_splice_read,
 	.llseek = cifs_llseek,
 #ifdef CONFIG_CIFS_POSIX
 	.ioctl	= cifs_ioctl,
@@ -676,7 +676,7 @@
 	.release = cifs_close,
 	.fsync = cifs_fsync,
 	.flush = cifs_flush,
-	.sendfile = generic_file_sendfile, /* BB removeme BB */
+	.splice_read = generic_file_splice_read,
 #ifdef CONFIG_CIFS_POSIX
 	.ioctl  = cifs_ioctl,
 #endif /* CONFIG_CIFS_POSIX */