Replace __strcpy_chk with __builtin___strcpy_chk

Replace __strcpy_chk with __builtin___strcpy_chk

Although _chk functions are exported in libc.so.6, their prototypes aren't
provided.  Their built versions are supported by compiler.  Replace
__strcpy_chk with __builtin___strcpy_chk to silence Clang error:

./tst-gnuglob-skeleton.c:225:3: error: call to undeclared function '__strcpy_chk'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
  225 |   __strcpy_chk (dir->d.d_name, filesystem[dir->idx].name, NAME_MAX);
      |   ^

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>