strlen is not dangerous if the string is known to be null
terminated (and MSVC does not warn about its use either).
For the cases in the decoder welsCodecTrace.cpp, the string
passed to all WriteString instances is produced by WelsVsnprintf
which always null terminates the buffer nowadays.
Additionally, as the string was passed to OutputDebugStringA
without any length specifier before, it was already assumed to
be null terminated.
The file name parameter passed to DumpDependencyRec and
DumpRecFrame in encoder.cpp is always null terminated,
which was already assumed as it is passed to WelsFopen as is.
As for the encoder utils.cpp, the strings returned by GetLogPath
are string constants that are null terminated.
As long as WelsFileHandle* is equal to FILE* this doesn't matter,
but for consistency use the WelsF* functions for all handles
opened by WelsFopen, and use WelsFileHandle* as type for it
instead of FILE*.
