build: disable Wstrict-prototypes

GTK won't build with strict-prototypes due to gtkitemfactory.h:

    /* We use () here to mean unspecified arguments. This is deprecated
     * as of C99, but we can't change it without breaking compatibility.
     * (Note that if we are included from a C++ program () will mean
     * (void) so an explicit cast will be needed.)
     */
    typedef	void	(*GtkItemFactoryCallback)  ();
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
Message-id: 1361367806-4599-2-git-send-email-aliguori@us.ibm.com

configure

@@ -283,7 +283,7 @@ sdl_config="${SDL_CONFIG-${cross_prefix}sdl-config}"
 # default flags for all hosts
 QEMU_CFLAGS="-fno-strict-aliasing $QEMU_CFLAGS"
 QEMU_CFLAGS="-Wall -Wundef -Wwrite-strings -Wmissing-prototypes $QEMU_CFLAGS"
-QEMU_CFLAGS="-Wstrict-prototypes -Wredundant-decls $QEMU_CFLAGS"
+QEMU_CFLAGS="-Wredundant-decls $QEMU_CFLAGS"
 QEMU_CFLAGS="-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE $QEMU_CFLAGS"
 QEMU_INCLUDES="-I. -I\$(SRC_PATH) -I\$(SRC_PATH)/include"
 if test "$debug_info" = "yes"; then