Fix the snprintf string to use the correct size format specifier

[kunaltyagi]

llu -> lu

[taketwo]

According to git blame we used to have lu, but that was changed 3 months ago: 7d0ee47

[kunaltyagi]

The issue might be 32 bit vs 64 bit for the size. In that case some other solution is needed

[kunaltyagi]

Found this in the reference

[taketwo]

Never seen something like this in the wild!

GCC seems to have a problem:

outofcore/src/visualization/viewport.cpp:184:39: error: unable to find string literal operator 'operator""PRIu64' with 'const char [14]', 'long unsigned int' arguments
             "%"PRIu64" points/%"PRIu64" mb", points_loaded, data_loaded/1024);

Maybe #include <inttypes.h> is needed?

[kunaltyagi]

Never seen something like this in the wild!

Yeah. I was just randomly searching when I read on SO that "zu" is specified for size_t which triggered me to read the reference page for "z".

Maybe #include <inttypes.h> is needed?

Yeah, didn't notice that small print

[taketwo]

[ 56%] Building CXX object outofcore/tools/CMakeFiles/pcl_outofcore_process.dir/outofcore_process.cpp.o
/__w/1/s/outofcore/src/visualization/viewport.cpp:185:13: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix]
             "%"PRIu64" points/%"PRIu64" mb", points_loaded, data_loaded/1024);
             ^
/__w/1/s/outofcore/src/visualization/viewport.cpp:185:22: warning: invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix]
             "%"PRIu64" points/%"PRIu64" mb", points_loaded, data_loaded/1024);
                      ^