broadcom/vc4: Fix infinite retry in vc4_bo_alloc()

broadcom/vc4: Fix infinite retry in vc4_bo_alloc()

cleared_and_retried is always reset to false when jumping to the retry
label, thus leading to an infinite retry loop.

Fix that by moving the cleared_and_retried variable definitions at the
beginning of the function.  While we're at it, move the create variable
with the other local variables and explicitly reset its content in the
retry path.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Fixes: 78087676c98aa8884ba92 "vc4: Restructure the simulator mode."