While debugging, it's currently really hard to identify controls
by their ID. Print the control name making the print more helpful.

With this change, the print changes from:

video1: VIDIOC_S_EXT_CTRLS: which=0xf010000, count=5, error_idx=4, request_fd=45, id/size=0x990ce8/1048, id/size=0x990ce9/12, id/size=0x990cea/480, id/size=0x990ceb/896, id/size=0x990cec/400

video1: VIDIOC_S_EXT_CTRLS: which=0xf010000, count=5, error_idx=4, request_fd=42, name=H264 Sequence Parameter Set, id/size=0x990ce8/1048, name=H264 Picture Parameter Set, id/size=0x990ce9/12, name=H264 Scaling Matrix, id/size=0x990cea/480, name=H264 Slice Parameters, id/size=0x990ceb/896, name=H264 Decode Parameters, id/size=0x990cec/400

For instance, this is specially helpful when the ioctl fails. Consider
the following example:

v4l2-ctrls: prepare_ext_ctrls: video1: pointer control id 0x990cec size too small, 400 bytes but 784 bytes needed
v4l2-ctrls: try_set_ext_ctrls: video1: video1: try_set_ext_ctrls_common failed (-14)
video1: VIDIOC_S_EXT_CTRLS: error -14: which=0xf010000, count=5, error_idx=5, request_fd=39, name=H264 Sequence Parameter Set, id/size=0x990ce8/1048, name=H264 Picture Parameter Set, id/size=0x990ce9/12, name=H264 Scaling Matrix, id/size=0x990cea/480, name=H264 Slice Parameters, id/size=0x990ceb/896, name=H264 Decode Parameters, id/size=0x990cec/400
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>