Minor improvement of dmg creation script

Author: Tom94

scripts/create-dmg.sh

@@ -3,7 +3,10 @@
 cd "$(dirname ${BASH_SOURCE[0]})"
 
 echo "Building backwards-compatible tev..."
-mkdir build-dmg && cd build-dmg
+
+BUILD_DIR="build-dmg"
+
+mkdir $BUILD_DIR && cd $BUILD_DIR
 MACOSX_DEPLOYMENT_TARGET=10.9
 cmake \
     -DCMAKE_OSX_SYSROOT=/Users/tom94/Projects/MacOSX-SDKs/MacOSX10.9.sdk/ \
@@ -16,7 +19,7 @@ cd ..
 echo "Creating dmg..."
 RESULT="../tev.dmg"
 test -f $RESULT && rm $RESULT
-./create-dmg/create-dmg --window-size 500 300 --icon-size 96 --volname "tev Installer" --app-drop-link 360 105 --icon tev.app 130 105 $RESULT ./build-dmg/tev.app
+./create-dmg/create-dmg --window-size 500 300 --icon-size 96 --volname "tev Installer" --app-drop-link 360 105 --icon tev.app 130 105 $RESULT $BUILD_DIR/tev.app
 
 echo "Removing temporary build dir..."
-rm -rf build-dmg
+rm -rf $BUILD_DIR