Corrected a syntax error in the old (non-Tcl/Tk) grX11su1.c code

that was introduced with a slew of updates back in October, as
noticed and reported (with solution) by J. Schonberg.

graphics/grX11su1.c

@@ -1443,7 +1443,7 @@ GrX11IconUpdate(w,text)
      XSetClassHint( grXdpy, wind, &class);
      if (text == NULL)
           return;
-     if ((brack = strchr(text,'[')) brack != text)
+     if ((brack = strchr(text,'[')) && (brack != text))
      {
      	  brack--;
 	  *brack = 0;