Fix last change in alloc.c.

* src/alloc.c (mark_maybe_object) [WIDE_EMACS_INT]: Avoid compiler
warning about 'overflow' being unused.
1 job for master in 62 minutes and 36 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
failed #6805
test-all

01:02:36

 
Name Stage Failure
failed
test-all Test
Makefile:318: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 1
make[2]: Leaving directory '/builds/emacs/emacs/test'
Makefile:293: recipe for target 'check-expensive' failed
make[1]: *** [check-expensive] Error 2
make[1]: Leaving directory '/builds/emacs/emacs/test'
make: *** [check-expensive] Error 2
Makefile:959: recipe for target 'check-expensive' failed
ERROR: Job failed: exit code 1