9p: Use the i_size_[read, write]() macros instead of using inode->i_size directly.

Change all occurrence of inode->i_size with i_size_read() or i_size_write()
as appropriate.

Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 68bf2af..de7690e 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -72,7 +72,7 @@
 			return err;
 		}
 		if (omode & P9_OTRUNC) {
-			inode->i_size = 0;
+			i_size_write(inode, 0);
 			inode->i_blocks = 0;
 		}
 		if ((file->f_flags & O_APPEND) && (!v9fs_extended(v9ses)))
@@ -239,9 +239,9 @@
 		*offset += total;
 	}
 
-	if (*offset > inode->i_size) {
-		inode->i_size = *offset;
-		inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
+	if (*offset > i_size_read(inode)) {
+		i_size_write(inode, *offset);
+		inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
 	}
 
 	if (n < 0)