Fix the makefile to work after the previous change, r160
Fix the makefile to work after the previous change, r160

The previous change replaced syscall_table.c with system_call_table.cc.

BUG=none
TEST="make test"

Review URL: http://codereview.chromium.org/7514033
ericmckean/seccompsandbox,ericmckean/seccompsandbox,cnbird1999/seccompsandbox,cnbird1999/seccompsandbox,cnbird1999/seccompsandbox,ericmckean/seccompsandbox