Replace to RBOOL macro

process.c

@@ -6723,12 +6723,7 @@ p_sys_setresgid(VALUE obj, VALUE rid, VALUE eid, VALUE sid)
 static VALUE
 p_sys_issetugid(VALUE obj)
 {
-    if (issetugid()) {
-	return Qtrue;
-    }
-    else {
-	return Qfalse;
-    }
+    return RBOOL(issetugid());
 }
 #else
 #define p_sys_issetugid rb_f_notimplement

re.c

@@ -3297,10 +3297,7 @@ rb_reg_eqq(VALUE re, VALUE str)
 	return Qfalse;
     }
     start = rb_reg_search(re, str, 0, 0);
-    if (start < 0) {
-	return Qfalse;
-    }
-    return Qtrue;
+    return RBOOL(start >= 0);
 }