nvh264dec, curlhttpsrc test, fix compiler warnings on raspbian

commit f4c2e92a:

nvcodec: fix compiler warning in certain setups
Fixes gstnvh264dec.c:648:12: warning: unused variable ‘ret’
compiler warning on raspbian where HAVE_NVCODEC_GST_GL is
not defined.

commit 27ac1acb:

tests: curlhttpsrc: fix compiler warning on raspbian
tests/check/elements/curlhttpsrc.c:142:14: warning: format ‘%lu’
expects argument of type ‘long unsigned int’, but argument 8 has
type ‘gsize’ {aka ‘unsigned int’}