fix strncat misuse

The third argument of strncat() tells how much data to append from
src, not the total size of the buffer.

Change uses of strncat() to strlcat(), which has the buffer overflow
protection behavior intended by the original author.

This fixes the following compiler warning:

In function 'strncat',
    inlined from 'print_type' at system/core/toolbox/lsof.c:76:12:
bionic/libc/include/string.h:142:5: warning: call to __builtin___strncat_chk might overflow destination buffer [enabled by default]

Change-Id: Id69edc641de3cb87d1867a409cd57b04b12f90a7