Remove redundant argument. Hopefully fixes compilation with Coq master.

2 jobs for master in 16 minutes and 28 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #21500
fp
build-coq.8.8.2

00:05:34

failed #21499
fp
build-coq.dev

00:16:28

 
Name Stage Failure
failed
build-coq.dev Build
Makefile.coq:312: recipe for target 'all' failed
make[1]: *** [all] Error 2
Makefile:6: recipe for target 'all' failed
make: *** [all] Error 2

real 1m57.994s
user 3m57.644s
sys 0m9.512s
ERROR: Job failed: exit code 1