i965/tex: Don't pass samples to miptree_create_for_teximage

i965/tex: Don't pass samples to miptree_create_for_teximage

In 76e2f390f9863a35, when Topi switched num_samples from 0 to 1 for
single-sampled, he accidentally switched the last parameter in the call
to miptree_create_for_teximage from 0 to 1 thinking it was num_samples
when it was actually layout_flags.  Switching from 0 to 1 added the
MIPTREE_LAYOUT_ACCELERATED_UPLOAD flag which causes us to allocate a
busy BO instead of an idle one.  This caused the subsequent CPU upload
to consistently stall.  The end result was a 15% performance drop in the
SynMark v7 DrvRes microbenchmark.  This restores the old behavior and
fixes the performance regression.

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Fixes: 76e2f390f9863a356d1419982dec705260d67eff
Bugzilla: https://bugs.freedesktop.org/102260
Cc: mesa-stable@lists.freedesktop.org