FPII-1951: Fix overflow in path building

Fix overflow in path building

An incorrect size was causing an unsigned value
to wrap, causing it to write past the end of
the buffer.

Bug: 28085658
Change-Id: Ie9625c729cca024d514ba2880ff97209d435a165
(cherry picked from commit 6ea6c04ca695e0f0b6bcf3ea4529b9fd74fee8e4)
1 file changed