drm/radeon/r600: only assign vb after we know space is available.
drm/radeon/r600: only assign vb after we know space is available.

This patch only changes this is the swap path, where it doesn't loop.

Signed-off-by: Robert Noland <e2ca747409018c6028240e8cecb1688df0451e4c@2hip.net>
Signed-off-by: Dave Airlie <f2295d84e358395675bc8031be58672073ae065e@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas