SDL_bmp.c: remove unused variable warnings
diff --git a/src/video/SDL_bmp.c b/src/video/SDL_bmp.c
index 3ee4056..1c0c8b2 100644
--- a/src/video/SDL_bmp.c
+++ b/src/video/SDL_bmp.c
@@ -192,23 +192,23 @@
 
     /* The Win32 BMP file header (14 bytes) */
     char magic[2];
-    Uint32 bfSize;
-    Uint16 bfReserved1;
-    Uint16 bfReserved2;
+    /* Uint32 bfSize; */
+    /* Uint16 bfReserved1; */
+    /* Uint16 bfReserved2; */
     Uint32 bfOffBits;
 
     /* The Win32 BITMAPINFOHEADER struct (40 bytes) */
     Uint32 biSize;
     Sint32 biWidth = 0;
     Sint32 biHeight = 0;
-    Uint16 biPlanes;
+    /* Uint16 biPlanes; */
     Uint16 biBitCount = 0;
     Uint32 biCompression = 0;
-    Uint32 biSizeImage;
-    Sint32 biXPelsPerMeter;
-    Sint32 biYPelsPerMeter;
+    /* Uint32 biSizeImage; */
+    /* Sint32 biXPelsPerMeter; */
+    /* Sint32 biYPelsPerMeter; */
     Uint32 biClrUsed = 0;
-    Uint32 biClrImportant;
+    /* Uint32 biClrImportant; */
 
     /* Make sure we are passed a valid data source */
     surface = NULL;
@@ -231,9 +231,9 @@
         was_error = SDL_TRUE;
         goto done;
     }
-    bfSize      = SDL_ReadLE32(src);
-    bfReserved1 = SDL_ReadLE16(src);
-    bfReserved2 = SDL_ReadLE16(src);
+    /* bfSize      = */ SDL_ReadLE32(src);
+    /* bfReserved1 = */ SDL_ReadLE16(src);
+    /* bfReserved2 = */ SDL_ReadLE16(src);
     bfOffBits   = SDL_ReadLE32(src);
 
     /* Read the Win32 BITMAPINFOHEADER */
@@ -241,26 +241,26 @@
     if (biSize == 12) {   /* really old BITMAPCOREHEADER */
         biWidth = (Uint32) SDL_ReadLE16(src);
         biHeight = (Uint32) SDL_ReadLE16(src);
-        biPlanes = SDL_ReadLE16(src);
+        /* biPlanes = */ SDL_ReadLE16(src);
         biBitCount = SDL_ReadLE16(src);
         biCompression = BI_RGB;
-        biSizeImage = 0;
-        biXPelsPerMeter = 0;
-        biYPelsPerMeter = 0;
+        /* biSizeImage = 0; */
+        /* biXPelsPerMeter = 0; */
+        /* biYPelsPerMeter = 0; */
         biClrUsed = 0;
-        biClrImportant = 0;
+        /* biClrImportant = 0; */
     } else if (biSize >= 40) {  /* some version of BITMAPINFOHEADER */
         Uint32 headerSize;
         biWidth = SDL_ReadLE32(src);
         biHeight = SDL_ReadLE32(src);
-        biPlanes = SDL_ReadLE16(src);
+        /* biPlanes = */ SDL_ReadLE16(src);
         biBitCount = SDL_ReadLE16(src);
         biCompression = SDL_ReadLE32(src);
-        biSizeImage = SDL_ReadLE32(src);
-        biXPelsPerMeter = SDL_ReadLE32(src);
-        biYPelsPerMeter = SDL_ReadLE32(src);
+        /* biSizeImage = */ SDL_ReadLE32(src);
+        /* biXPelsPerMeter = */ SDL_ReadLE32(src);
+        /* biYPelsPerMeter = */ SDL_ReadLE32(src);
         biClrUsed = SDL_ReadLE32(src);
-        biClrImportant = SDL_ReadLE32(src);
+        /* biClrImportant = */ SDL_ReadLE32(src);
 
         /* 64 == BITMAPCOREHEADER2, an incompatible OS/2 2.x extension. Skip this stuff for now. */
         if (biSize != 64) {