waffle: return accurate result from wegl_platform_init()
waffle: return accurate result from wegl_platform_init()

wegl_platform_init() now returns false if dlopen or dlsym fails.

Signed-off-by: Frank Henigman <4f3ccfa167f952ff7263448ff4377acff6a23e5c@google.com>
Reviewed-by: Emil Velikov <4c996f2f093ddd0585a556460b4cc3ba555546ef@gmail.com>
Reviewed-by: Chad Versace <a557f7f75bf28dc19ac99107f5cc7cd6b3fbdb1a@intel.com>

fjhenigman/waffle,dcbaker/waffle,waffle-gl/waffle,fjhenigman/waffle,maurossi/waffle,waffle-gl/waffle,waffle-gl/waffle,chadversary/waffle,evelikov/waffle,chadversary/waffle,evelikov/waffle,maurossi/waffle,waffle-gl/waffle,fjhenigman/waffle,evelikov/waffle,dcbaker/waffle,chadversary/waffle,dcbaker/waffle,maurossi/waffle