tools:iio: catch errors in string allocation

This patch catches errors in string allocation in generic_buffer.c,
iio_event_monitor.c, iio_utils.c and lsiio.c.

Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --cc tools/iio/generic_buffer.c
Simple merge

diff --cc tools/iio/iio_event_monitor.c
Simple merge

diff --cc tools/iio/iio_utils.c
Simple merge

diff --cc tools/iio/lsiio.c
Simple merge