egl: fix deadlock in malloc error path

Fixes: cb0980e6 ("egl: move alloc & init out of _eglBuiltInDriver{DRI2,Haiku}")
Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
(cherry picked from commit 43d47040)