ext4: check error return from ext4_write_inline_data_end()

commit 42c832debbbf819f6c4ad8601baa559c44105ba4 upstream.

The function ext4_write_inline_data_end() can return an error.  So we
need to assign it to a signed integer variable to check for an error
return (since copied is an unsigned int).

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>