[SDL] Compile warnings (wayland+clang 3.9)

[M. Gerhardy]

FYI:

sdl2/src/video/wayland/SDL_waylandevents.c:267:1: warning: missing field
'frame' initializer [-Wmissing-field-initializers]
sdl2/src/video/wayland/SDL_waylandevents.c:399:1: warning: missing field
'repeat_info' initializer [-Wmissing-field-initializers]
sdl2/src/video/wayland/SDL_waylandevents.c:431:1: warning: missing field
'name' initializer [-Wmissing-field-initializers]
sdl2/src/video/wayland/SDL_waylandvideo.c:331:1: warning: missing field
'global_remove' initializer [-Wmissing-field-initializers]

clang version 3.9.0-svn262954-1 (trunk)

Regards
Martin