firmware: read firmware size using i_size_read()

There is no need to read attr because inode structure contains size
of the file. Use i_size_read() instead.
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Acked-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/firmware_class.c

@@ -284,26 +284,15 @@ static const char * const fw_path[] = {
 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
 
-/* Don't inline this: 'struct kstat' is biggish */
-static noinline_for_stack int fw_file_size(struct file *file)
-{
-	struct kstat st;
-	if (vfs_getattr(&file->f_path, &st))
-		return -1;
-	if (!S_ISREG(st.mode))
-		return -1;
-	if (st.size != (int)st.size)
-		return -1;
-	return st.size;
-}
-
 static int fw_read_file_contents(struct file *file, struct firmware_buf *fw_buf)
 {
 	int size;
 	char *buf;
 	int rc;
 
-	size = fw_file_size(file);
+	if (!S_ISREG(file_inode(file)->i_mode))
+		return -EINVAL;
+	size = i_size_read(file_inode(file));
 	if (size <= 0)
 		return -EINVAL;
 	buf = vmalloc(size);