Fix some comment typos

source/scale_gcc.cc

 /*
  *  Copyright 2013 The LibYuv Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS. All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 849 matching lines @@
     "movdqa    %%xmm2,%%xmm1                   \n"
     "paddd     %%xmm3,%%xmm2                   \n"
     MEMOPARG(movzwl,0x00,1,3,1,k2)             //  movzwl  (%1,%3,1),%k2
     "movd      %k2,%%xmm0                      \n"
     "psrlw     $0x9,%%xmm1                     \n"
     MEMOPARG(movzwl,0x00,1,4,1,k2)             //  movzwl  (%1,%4,1),%k2
     "movd      %k2,%%xmm4                      \n"
     "pshufb    %%xmm5,%%xmm1                   \n"
     "punpcklwd %%xmm4,%%xmm0                   \n"
     "psubb     %8,%%xmm0                       \n"  // make pixels signed.
-    "pxor      %%xmm6,%%xmm1                   \n"  // 128 -f = (f ^ 127 ) + 1
+    "pxor      %%xmm6,%%xmm1                   \n"  // 128 - f = (f ^ 127 ) + 1
     "paddusb   %%xmm7,%%xmm1                   \n"
     "pmaddubsw %%xmm0,%%xmm1                   \n"
     "pextrw    $0x1,%%xmm2,%k3                 \n"
     "pextrw    $0x3,%%xmm2,%k4                 \n"
     "paddw     %9,%%xmm1                       \n"  // make pixels unsigned.
     "psrlw     $0x7,%%xmm1                     \n"
     "packuswb  %%xmm1,%%xmm1                   \n"
     "movd      %%xmm1,%k2                      \n"
     "mov       %w2," MEMACCESS(0) "            \n"
     "lea       " MEMLEA(0x2,0) ",%0            \n"
@@ skipping 432 matching lines @@
   );
   return num;
 }
 
 #endif  // defined(__x86_64__) || defined(__i386__)
 
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif