drm/stm: Avoid using val uninitialized in ltdc_set_ycbcr_config()

Clang warns:

  drivers/gpu/drm/stm/ltdc.c:625:2: warning: variable 'val' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
          default:
          ^~~~~~~
  drivers/gpu/drm/stm/ltdc.c:635:2: note: uninitialized use occurs here
          val |= LxPCR_YCEN;
          ^~~
  drivers/gpu/drm/stm/ltdc.c:600:9: note: initialize the variable 'val' to silence this warning
          u32 val;
                 ^
                  = 0
  1 warning generated.

Use a return instead of break in the default case to fix the warning.
Add an error message so that this return is not silent, which could hide
issues in the future.

Fixes: 484e72d3146b ("drm/stm: ltdc: add support of ycbcr pixel formats")
Link: https://github.com/ClangBuiltLinux/linux/issues/1575
Acked-by: Yannick Fertre <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Reviewed-by: Raphael Gallais-Pou <[email protected]>
Signed-off-by: Nathan Chancellor <[email protected]>
Signed-off-by: Philippe Cornu <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

0 files changed, 0 insertions, 0 deletions