libstdc++: testsuite: cast getpid result

On vxworks, in kernel mode, getpid's return type is a pointer type, so
std::to_string on it fails overload resolution.  Restore the type cast
from the original patch that suggested adding the pid.

for  libstdc++-v3/ChangeLog

	* testsuite/util/testsuite_fs.h (nonexistent_path): Convert
	the getpid result to an integral type.
1 file changed