kernel: Increase +1 size of destination buffer to avoid overflow

kernel: Increase +1 size of destination buffer to avoid overflow

Increase the size of the destination buffer to one more than the data to be copied through sscanf.
For example, if we want to copy BUFF_MAX size from source buffer
then destination buffer size should be larger than BUFF_MAX (e.g., BUFF_MAX + 1)
to avoid buffer overflow.
By doing so, regardless of the size of the source buffer,
only up to BUFF_MAX size is copied to the destination buffer.

Change-Id: I63cefd0f325d89fa41b6fe4241f871191c0884fa
Signed-off-by: Unsung Lee <unsung.lee@samsung.com>