Loopfilter: bug fix in sb_type usage

Was always using sb_type of first column in a row of 8x8 units when
determining decoded block edges as a subcondition for loop filter
skipping.

Change-Id: Ib17554633a63a90b70cdaa7bed65db035a8ad9d8

vp9/common/vp9_loopfilter.c

diff --git a/vp9/common/vp9_loopfilter.c b/vp9/common/vp9_loopfilter.c
index d715e91..cb80d14 100644
--- a/vp9/common/vp9_loopfilter.c
+++ b/vp9/common/vp9_loopfilter.c
@@ -679,12 +679,12 @@
       const int skip_this = mi[c].mbmi.mb_skip_coeff
                             && mi[c].mbmi.ref_frame != INTRA_FRAME;
       // left edge of current unit is block/partition edge -> no skip
-      const int block_edge_left = b_width_log2(mi->mbmi.sb_type) ?
-          !(c & ((1 << (b_width_log2(mi->mbmi.sb_type)-1)) - 1)) : 1;
+      const int block_edge_left = b_width_log2(mi[c].mbmi.sb_type) ?
+          !(c & ((1 << (b_width_log2(mi[c].mbmi.sb_type)-1)) - 1)) : 1;
       const int skip_this_c = skip_this && !block_edge_left;
       // top edge of current unit is block/partition edge -> no skip
-      const int block_edge_above = b_height_log2(mi->mbmi.sb_type) ?
-          !(r & ((1 << (b_height_log2(mi->mbmi.sb_type)-1)) - 1)) : 1;
+      const int block_edge_above = b_height_log2(mi[c].mbmi.sb_type) ?
+          !(r & ((1 << (b_height_log2(mi[c].mbmi.sb_type)-1)) - 1)) : 1;
       const int skip_this_r = skip_this && !block_edge_above;
       const TX_SIZE tx_size = plane ? get_uv_tx_size(xd) : mi[c].mbmi.txfm_size;