utils: make sure slow GST_READ_UINT* variants don't have unexpected side effects
utils: make sure slow GST_READ_UINT* variants don't have unexpected side effects

Fixes unit test on systems where unaligned memory access is not possible.

https://bugzilla.gnome.org/show_bug.cgi?id=695599

lubosz/gstreamer,jpxiong/gstreamer,lovebug356/gstreamer,jpakkane/gstreamer,collects/gstreamer,lovebug356/gstreamer,justinjoy/gstreamer,lubosz/gstreamer,cfoch/gstreamer,collects/gstreamer,StreamUtils/gstreamer,mparis/gstreamer,krieger-od/gstreamer,cablelabs/gstreamer,Lachann/gstreamer,krieger-od/gstreamer,cfoch/gstreamer,krieger-od/gstreamer,shelsonjava/gstreamer,Lachann/gstreamer,collects/gstreamer,StreamUtils/gstreamer,justinjoy/gstreamer,surround-io/gstreamer,surround-io/gstreamer,jpakkane/gstreamer,mparis/gstreamer,krichter722/gstreamer,justinjoy/gstreamer,cfoch/gstreamer,krichter722/gstreamer,collects/gstreamer,lubosz/gstreamer,lubosz/gstreamer,cablelabs/gstreamer,ensonic/gstreamer,krichter722/gstreamer,jpakkane/gstreamer,krieger-od/gstreamer,cfoch/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,jpxiong/gstreamer,ensonic/gstreamer,mparis/gstreamer,lubosz/gstreamer,lovebug356/gstreamer,krichter722/gstreamer,collects/gstreamer,lovebug356/gstreamer,StreamUtils/gstreamer,mparis/gstreamer,surround-io/gstreamer,justinjoy/gstreamer,Lachann/gstreamer,jpxiong/gstreamer,cablelabs/gstreamer,justinjoy/gstreamer,StreamUtils/gstreamer,ensonic/gstreamer,centricular/gstreamer,centricular/gstreamer,centricular/gstreamer,surround-io/gstreamer,jpakkane/gstreamer,shelsonjava/gstreamer,shelsonjava/gstreamer,StreamUtils/gstreamer,ensonic/gstreamer,krichter722/gstreamer,jpakkane/gstreamer,cablelabs/gstreamer,cfoch/gstreamer,krieger-od/gstreamer,Lachann/gstreamer,shelsonjava/gstreamer,surround-io/gstreamer,centricular/gstreamer,shelsonjava/gstreamer,Lachann/gstreamer,ensonic/gstreamer,centricular/gstreamer,mparis/gstreamer,lovebug356/gstreamer,jpxiong/gstreamer