the simple changes that might fix linux

gl/glextensions.c

@@ -1,9 +1,32 @@
+/*
+ * QEMU OpenGL extensions
+ *
+ * Copyright (c) 2015 espes
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 or
+ * (at your option) version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
 #include "gloffscreen.h"
 #include "glextensions.h"
 
+#ifdef __APPLE__
 void (*glFrameTerminatorGREMEDY)(void);
+#endif
 
 void glextensions_init(void)
 {
-    glFrameTerminatorGREMEDY = glo_get_extension_proc("glFrameTerminatorGREMEDY");
+#ifdef __APPLE__
+    glFrameTerminatorGREMEDY =
+        glo_get_extension_proc("glFrameTerminatorGREMEDY");
+#endif
 }

gl/glextensions.h

@@ -1,7 +1,27 @@
+/*
+ * QEMU OpenGL extensions
+ *
+ * Copyright (c) 2015 espes
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 or
+ * (at your option) version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
 #ifndef GLEXTEENSIONS_H_
 #define GLEXTEENSIONS_H_
 
+#ifdef __APPLE__
 extern void (*glFrameTerminatorGREMEDY)(void);
+#endif
 
 void glextensions_init(void);
 

gl/gloffscreen.h

@@ -39,6 +39,7 @@
 #include <GL/gl.h>
 #include <GL/glext.h>
 #else
+#include <GL/glew.h>
 #include <GL/gl.h>
 #endif