Correct a comment

BUG=aomedia:2616

Change-Id: Ibe8bdf320ea8ed06dd86c668a3e53fce14b077c9
diff --git a/aom_ports/ppc_cpudetect.c b/aom_ports/ppc_cpudetect.c
index 82b4f58..ce4d5ae 100644
--- a/aom_ports/ppc_cpudetect.c
+++ b/aom_ports/ppc_cpudetect.c
@@ -45,7 +45,7 @@
   unsigned int i;
   uint64_t buf[64];
 
-  // If VPX_SIMD_CAPS is set then allow only those capabilities.
+  // If AOM_SIMD_CAPS_MASK is set then allow only those capabilities.
   if (!cpu_env_flags(&flags)) {
     return flags;
   }