Simplify one variable setting.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@10776 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

configure

@@ -1246,9 +1246,7 @@ EOF
     exit 1;
 fi
 
-if disabled static; then
-    LIBNAME=""
-fi
+disabled static && LIBNAME=""
 
 if ! enabled libogg; then
     enabled libtheora && die "libogg must be enabled to enable libtheora."