Unsquashfs was segfaulting.  When examining in gdb the stack was corrupt.
I found that converting the variable length arrays to malloc caused the
stack corruption to not happen and the segfault went away.  This is due to
the musl pthread stack size being 80k by default.  So the chance of a stack
overflow is high.

Signed-off-by: Colby Whitney <colby.whitney@luxul.com>