V4L/DVB (11736): videobuf: modify return value of VIDIOC_REQBUFS ioctl
V4L/DVB (11736): videobuf: modify return value of VIDIOC_REQBUFS ioctl

The V4L2 ioctls usually return 0 when the operation was successful
and -1 in case of error. Currently VIDIOC_REQBUFS returns the
number of buffers which is redundant because this information is
available in count field of struct v4l2_requestbuffers. The
V4L2 API specification, revision 0.24 [1] explicitly specifies for
VIDIOC_REQBUFS that the return value shall be 0 on success.

The patch was tested with v4l-test 0.13 [2] with vivi driver.

References:
[1] V4L2 API specification, revision 0.24
    http://v4l2spec.bytesex.org/spec/r13696.htm

[2] v4l-test: Test environment for Video For Linux Two API
    http://v4l-test.sourceforge.net/

Signed-off-by: Márton Németh <8fdce27e837180693215edc025691c83b7d5795b@freemail.hu>
Signed-off-by: Mauro Carvalho Chehab <ad86ba2154032c9f55743a190faa2459a9d61d42@redhat.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs