gpu: pvr: no need to check for retry failures in PVRSRVMISR

gpu: pvr: no need to check for retry failures in PVRSRVMISR

ProcessQueues can't fail any more with a 'retry' error, so checking for
this is not needed. Previously ProcessQueues could fail if sQProcessResource
is locked by someone else. Since sQProcessResource is removed by a previous
change in this patchset that race condition can't happen.

Signed-off-by: Imre Deak <imre.deak@nokia.com>
CC: Mark Underwood <mark.underwood@imgtec.com>
CC: Mark Riding <mark.riding@imgtec.com>
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@nokia.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@nokia.com>