surfaceflinger: Remove unused variable

The stack variable 'numTypes' was set but never used in
Display::getHdrCapabilities(), so we remove it.

Test: Built aosp_arm-eng
Change-Id: I9d823feb73a14a416d21ad98396622fe72beb730
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.cpp b/services/surfaceflinger/DisplayHardware/HWC2.cpp
index ab4a4b2..affe505 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWC2.cpp
@@ -467,7 +467,6 @@
 Error Display::getHdrCapabilities(
         std::unique_ptr<HdrCapabilities>* outCapabilities) const
 {
-    uint32_t numTypes = 0;
     float maxLuminance = -1.0f;
     float maxAverageLuminance = -1.0f;
     float minLuminance = -1.0f;
@@ -480,7 +479,6 @@
     for (auto type : intTypes) {
         types.push_back(static_cast<int32_t>(type));
     }
-    numTypes = types.size();
     if (error != Error::None) {
         return error;
     }