ALSA: pcm: Use ERESTARTSYS instead of EINTR in OSS emulation

ALSA: pcm: Use ERESTARTSYS instead of EINTR in OSS emulation

BugLink: http://bugs.launchpad.net/bugs/1773233
commit c64ed5dd9feba193c76eb460b451225ac2a0d87b upstream.

Fix the last standing EINTR in the whole subsystem.  Use more correct
ERESTARTSYS for pending signals.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Khalid Elmously <khalid.elmously@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>