chg: fix spelling in the error message about error waiting for cmdserver

This is a trivial spelling and grammar fix.

contrib/chg/chg.c

@@ -266,7 +266,7 b' cleanup:'
 	} else if (WIFSIGNALED(pst)) {
 		abortmsg("cmdserver killed by signal %d", WTERMSIG(pst));
 	} else {
-		abortmsg("error white waiting cmdserver");
+		abortmsg("error while waiting for cmdserver");
 	}
 	return NULL;
 }