app: aboot: Replace strncpy to strlcpy.

Replace strncpy to strlcpy. This is required as strncpy function
does not guarantee that the resultant string is NULL-terminated.
It also does not provide a standard way to check whether truncation
has occurred or not.

Change-Id: Iccde0dc8f3c3b3a9c29fcec8eb011863bc5b803c
1 file changed