MFC r353452: Improve remote address scanning in SCTP

Ensure that local variables are reset to their initial value when
dealing with error cases in a loop over all remote addresses.
This issue was found and reported by OSS_Fuzz in:
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=18080
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=18086
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=18121
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=18163