Fix EGLContextCompatibilityTest.

The check for "IsPlatformAvailable" was inverted. We were incorrectly
trying only to create a context on invalid configs.

Bug: angleproject:4449
Change-Id: I03fbdc7794a338a55b9dc64521915a8be247bf35
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2376045
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/tests/egl_tests/EGLContextCompatibilityTest.cpp b/src/tests/egl_tests/EGLContextCompatibilityTest.cpp
index 17208fd..bbf6813 100644
--- a/src/tests/egl_tests/EGLContextCompatibilityTest.cpp
+++ b/src/tests/egl_tests/EGLContextCompatibilityTest.cpp
@@ -71,6 +71,10 @@
             return windowSurfaceTest;
     }
 
+    // Linux failures: http://anglebug.com/4990
+    if (IsLinux())
+        return true;
+
     return false;
 }
 
@@ -489,7 +493,7 @@
     for (EGLint renderer : renderers)
     {
         PlatformParameters params = FromRenderer(renderer);
-        if (IsPlatformAvailable(params))
+        if (!IsPlatformAvailable(params))
             continue;
 
         EGLint dispattrs[] = {EGL_PLATFORM_ANGLE_TYPE_ANGLE, renderer, EGL_NONE};