update typos in documentation

doc/man/man5/slurm.conf.5

@@ -1325,7 +1325,7 @@ initiation time of individual jobs.
 The number of seconds between iterations.
 Higher values result in less overhead and responsiveness.
 The default value is 5 seconds on BlueGene systems and 10 seconds otherwise.
-This options apply only to \fBSchedulerType=sched/backfill\fR.
+This option applies only to \fBSchedulerType=sched/backfill\fR.
 .TP
 \fBmax_job_bf=#\fR
 The maximum number of jobs to attempt backfill scheduling for
@@ -1337,7 +1337,7 @@ The default value is 50.
 In the case of large clusters (more than 1000 nodes) configured with
 \fBSelectType=select/cons_res\fR, setting a smaller value may be
 desirable.
-This options apply only to \fBSchedulerType=sched/backfill\fR.
+This option applies only to \fBSchedulerType=sched/backfill\fR.
 .RE
 
 .TP