Don't realloc processes table in each run
Don't realloc processes table in each run

This fixes a memory leak if calling fork_and_trace() multiple times in
the same process (which doesn't happen in reprozip anyway).

ViDA-NYU/reprozip,ViDA-NYU/reprozip,ViDA-NYU/reprozip,JosuaKrause/reprozip,ViDA-NYU/reprozip,JosuaKrause/reprozip,JosuaKrause/reprozip,JosuaKrause/reprozip,ViDA-NYU/reprozip