Remove redundant control check

control was set, but it was not ever used because it was set
again some lines later.

st.c

@@ -2648,7 +2648,6 @@ tputc(char *c, int len) {
 			c = "\357\277\275";	/* UTF_INVALID */
 			width = 1;
 		}
-		control = ISCONTROLC1(unicodep);
 		ascii = unicodep;
 	}