Use strlcpy() instead of strncpy() to copy the string returned by
setlocale() so that static analyzers know that the string is NUL
terminated. This was causing a false positive in Coverity even
though the longest string returned by setlocale() is ENCODING_LEN
(31) and we are copying into a 64 byte buffer. This change is also
a bit of an optimization since we don't need the strncpy() feature
of padding the rest of the destination buffer with NUL characters.

Reported by: Coverity
CID: 974654