Move hard drive from macbook pro to macbook air
As far as I can see both MacBook's using different SSD's. Take a look on iFixit.com and the image taken from the tutorial 

MacBook Air 13" Mid 2012 Solid-State Drive
. 

MacBook Pro 15" Retina Display Mid 2012 SSD


MacBook Pro 15" Retina Display Mid 2012 SSD Replacement
MacBook Air 13" Mid 2012 Solid-State Drive Replacement

I guess it would be much easier and faster using Time Machine, Superduper, Disk Utility, CCC...