Fixing some warnings on Linux

There were only a few warnings left, so I fixed them and enabled the unused variable warning by removing the "-Wno-unused" flag. Only the -Wno-unused-parameter remains for now (could be removed later).
Review URL: https://codereview.chromium.org/12480002

git-svn-id: http://skia.googlecode.com/svn/trunk@8030 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/gmmain.cpp b/gm/gmmain.cpp
index 26242e6..a817a17 100644
--- a/gm/gmmain.cpp
+++ b/gm/gmmain.cpp
@@ -1165,7 +1165,9 @@
     bool doRTree = true;
     bool doTileGrid = true;
     bool doVerbose = false;
+#if SK_SUPPORT_GPU
     bool disableTextureCache = false;
+#endif
     SkTDArray<size_t> configs;
     SkTDArray<size_t> excludeConfigs;
     SkTDArray<SkScalar> tileGridReplayScales;
@@ -1302,7 +1304,9 @@
         } else if (strcmp(*argv, "--noserialize") == 0) {
             doSerialize = false;
         } else if (strcmp(*argv, "--notexturecache") == 0) {
+#if SK_SUPPORT_GPU
             disableTextureCache = true;
+#endif
         } else if (strcmp(*argv, "--tiledPipe") == 0) {
             doTiledPipe = true;
         } else if (!strcmp(*argv, "--verbose") || !strcmp(*argv, "-v")) {