src: fix typo in probe description

This fixes a typo in a probe description added in
dc1996d.

PR-URL: #15397
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Ruben Bridgewater <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Luigi Pinca <[email protected]>

src/v8ustack.d

@@ -522,7 +522,7 @@ dtrace:helper:ustack:
 		NO_SHARED_FUNCTION_NAME_SENTINEL;
 }
 
-dtracr:helper:ustack:
+dtrace:helper:ustack:
 /!this->done && this->hassharedname/
 {
 	LOAD_STRFIELDS(this->funcrawnamestr, this->funcnamelen,