The appl pointer needs to be updated only when snd_pcm_mmap_commit() is
successfully returned. Or it shouldn't be updated.
This is to fix the avail_update()'s result is incorrect when returns error.
(From OE-Core rev: fcd7e439497174256a5c467532aad402f4d19ca1)
Signed-off-by: Yuqing Zhu <carol.zhu@nxp.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>