DOCSP-26802 Fix typo in serverStatus.txt (#6216)

Author: milkie

source/reference/command/serverStatus.txt

@@ -229,9 +229,9 @@ asserts
 
 .. serverstatus:: asserts.rollovers
 
-   The number of times that the rollover counters have rolled over
+   The number of times that the assert counters have rolled over
    since the last time the MongoDB process started. The counters will
-   rollover to zero after 2\ :superscript:`30` assertions. Use this
+   roll over to zero after 2\ :superscript:`30` assertions. Use this
    value to provide context to the other values in the
    :serverstatus:`asserts` data structure.