Utilized local var to prevent double search
Utilized local var to prevent double search

`$navigation.find '[data-role="prev"]'` was being run twice.

Once saved to the local variables `$prev` and `$next`, and again to actually use the elements because the local variables were never used.  This change makes use of them and removes the duplicate search.
sorich87/bootstrap-tour,suryasingh/bootstrap-tour,LightmakerCanada/bootstrap-tour,tvanfosson/bootstrap-tour,Youraiseme/bootstrap-tour,ddeath/bootstrap-tour,marclaporte/bootstrap-tour,yodiyo/bootstrap-tour,suryasingh/bootstrap-tour,barnyp/bootstrap-tour,wski/bootstrap-tour,yodiyo/bootstrap-tour,LightmakerCanada/bootstrap-tour,iron-hulk/bootstrap-tour,supriyantomaftuh/bootstrap-tour,walhalatur/bootstrap-tour,ozone-development/bootstrap-tour,supriyantomaftuh/bootstrap-tour,barnyp/bootstrap-tour,kararade/bootstrap-tour,Olarewaju/bootstrap-tour,harrissoerja/bootstrap-tour,iron-hulk/bootstrap-tour,ozone-development/bootstrap-tour,emaiqi/bootstrap-tour,Youraiseme/bootstrap-tour,Olarewaju/bootstrap-tour,wski/bootstrap-tour,sorich87/bootstrap-tour,kararade/bootstrap-tour,walhalatur/bootstrap-tour,marclaporte/bootstrap-tour,ddeath/bootstrap-tour,harrissoerja/bootstrap-tour,tvanfosson/bootstrap-tour,emaiqi/bootstrap-tour