egl: use _eglError's 'msg' as an actual message in EGL_KHR_debug

egl: use _eglError's 'msg' as an actual message in EGL_KHR_debug

Seemingly, the original intent behind _eglError's 'msg' was aimed to
provide a function name.

At some point, people started using it the way EGL_KHR_debug's
callback() message is meant to be used. Aka providing meaningful
information to the developer/user.

Swap the funcName/msg argument order in the _eglDebugReport() call.
The 'funcName' variable is implicitly set, props to the
_eglSetFuncName() call at the start of each public entrypoint.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>