Uninitialized Memory Bug Correction

BUG = aomedia:2574
Extending to remaining HighBD functions

Change-Id: I86f9f5047d639520e0010a3e1f0c4c5502715fb6
diff --git a/aom_dsp/x86/intrapred_avx2.c b/aom_dsp/x86/intrapred_avx2.c
index 58789c3..546ee74 100644
--- a/aom_dsp/x86/intrapred_avx2.c
+++ b/aom_dsp/x86/intrapred_avx2.c
@@ -1989,7 +1989,7 @@
     int base_x = (-y * dx) >> frac_bits_x;
     int base_shift = 0;
     if (base_x < (min_base_x - 1)) {
-      base_shift = (min_base_x - base_x - 1) >> upsample_above;
+      base_shift = (min_base_x - base_x) >> upsample_above;
     }
     int base_min_diff =
         (min_base_x - base_x + upsample_above) >> upsample_above;
@@ -2115,7 +2115,7 @@
     int base_x = (-y * dx) >> frac_bits_x;
     int base_shift = 0;
     if (base_x < (min_base_x - 1)) {
-      base_shift = (min_base_x - base_x - 1) >> upsample_above;
+      base_shift = (min_base_x - base_x) >> upsample_above;
     }
     int base_min_diff =
         (min_base_x - base_x + upsample_above) >> upsample_above;
@@ -2237,7 +2237,7 @@
     int base_x = (-y * dx) >> frac_bits_x;
     int base_shift = 0;
     if (base_x < (min_base_x - 1)) {
-      base_shift = (min_base_x - base_x - 1) >> upsample_above;
+      base_shift = (min_base_x - base_x) >> upsample_above;
     }
     int base_min_diff =
         (min_base_x - base_x + upsample_above) >> upsample_above;
@@ -2387,7 +2387,7 @@
     int base_x = (-y * dx) >> frac_bits_x;
     int base_shift = 0;
     if (base_x < (min_base_x - 1)) {
-      base_shift = (min_base_x - base_x - 1) >> upsample_above;
+      base_shift = (min_base_x - base_x) >> upsample_above;
     }
     int base_min_diff =
         (min_base_x - base_x + upsample_above) >> upsample_above;