avutil/hwcontext_vulkan: Include hwcontext.h

struct Foo * declares a new type (namely struct Foo) if there is no declaration of struct Foo already visible in the current scope; otherwise it is just a pointer to an element of the already declared type "struct Foo". There is a gotcha with the first case: struct Foo is only declared in its scope; a later declaration of struct Foo in an enclosing scope declares a different type. This happens in hwcontext_vulkan.h if it is included before hwcontext.h, because some declarations of struct AVHWDeviceContext and struct AVHWFramesContext have function prototype scope. Compilers warn about this (during checkheaders): ‘struct AVHWDeviceContext’ declared inside parameter list will not be visible outside of this definition or declaration Fix this by including hwcontext.h.

ARAndreas Rheinhardt committed 2 years ago