cairo: Fix cairo_image_surface_get_data binding
cairo: Fix cairo_image_surface_get_data binding

Fixes bug 579803.

phako/vala,GNOME/vala,spidermonkdust/vala,flobrosch/vala-fixes,GNOME/vala,spidermonkdust/vala,flobrosch/vala-fixes,kamanashisroy/aroop,themiwi/vala,Distrotech/vala,playya/vala,jessevdk/vala,playya/vala,themiwi/vala,Jc2k/vala,jessevdk/vala,Jc2k/vala,severinh/vala,lovebug356/vala,frida/vala,frida/vala,spidermonkdust/vala,kamanashisroy/aroop,tjol/vala-tjol,rvu95/vala,playya/vala,phako/vala,rvu95/vala,severinh/vala,lovebug356/vala,tjol/vala-tjol,themiwi/vala,rvu95/vala,flobrosch/vala-fixes,frida/vala,frida/vala,xdave/pvala,severinh/vala,GNOME/vala,frida/vala,kamanashisroy/aroop,tjol/vala-tjol,GNOME/vala,jessevdk/vala,Distrotech/vala,Distrotech/vala