Fixed crash if initialization of EGL failed but was tried again later.

The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().

Xcode-iOS/Template/SDL iOS Application/main.c

@@ -0,0 +1,98 @@
+/*
+ *  rectangles.c
+ *  written by Holmes Futrell
+ *  use however you want
+ */
+
+#include "SDL.h"
+#include <time.h>
+
+#define SCREEN_WIDTH 320
+#define SCREEN_HEIGHT 480
+
+int
+randomInt(int min, int max)
+{
+    return min + rand() % (max - min + 1);
+}
+
+void
+render(SDL_Renderer *renderer)
+{
+
+    Uint8 r, g, b;
+
+    /* Clear the screen */
+    SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+    SDL_RenderClear(renderer);
+
+    /*  Come up with a random rectangle */
+    SDL_Rect rect;
+    rect.w = randomInt(64, 128);
+    rect.h = randomInt(64, 128);
+    rect.x = randomInt(0, SCREEN_WIDTH);
+    rect.y = randomInt(0, SCREEN_HEIGHT);
+
+    /* Come up with a random color */
+    r = randomInt(50, 255);
+    g = randomInt(50, 255);
+    b = randomInt(50, 255);
+    SDL_SetRenderDrawColor(renderer, r, g, b, 255);
+
+    /*  Fill the rectangle in the color */
+    SDL_RenderFillRect(renderer, &rect);
+
+    /* update screen */
+    SDL_RenderPresent(renderer);
+}
+
+int
+main(int argc, char *argv[])
+{
+
+    SDL_Window *window;
+    SDL_Renderer *renderer;
+    int done;
+    SDL_Event event;
+
+    /* initialize SDL */
+    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+        printf("Could not initialize SDL\n");
+        return 1;
+    }
+
+    /* seed random number generator */
+    srand(time(NULL));
+
+    /* create window and renderer */
+    window =
+        SDL_CreateWindow(NULL, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT,
+                         SDL_WINDOW_OPENGL);
+    if (!window) {
+        printf("Could not initialize Window\n");
+        return 1;
+    }
+
+    renderer = SDL_CreateRenderer(window, -1, 0);
+    if (!renderer) {
+        printf("Could not create renderer\n");
+        return 1;
+    }
+
+    /* Enter render loop, waiting for user to quit */
+    done = 0;
+    while (!done) {
+        while (SDL_PollEvent(&event)) {
+            if (event.type == SDL_QUIT) {
+                done = 1;
+            }
+        }
+        render(renderer);
+        SDL_Delay(1);
+    }
+
+    /* shutdown SDL */
+    SDL_Quit();
+
+    return 0;
+}