gallium/tgsi: fix overflow in parse property
gallium/tgsi: fix overflow in parse property

In parse_identifier, it doesn't stop copying '*pcur'
untill encounter the NULL. As the 'ret' has a
fixed-size buffer, if the '*pcur' has a long string,
there will be a buffer overflow. This patch avoid this.

Signed-off-by: Li Qiang <67c8c0472d6f8c612396f434e8d98025d1a01b50@gmail.com>
Signed-off-by: Marek Olšák <8c7344a1abdb103e79ecfd488098373070c3c70e@amd.com>
Reviewed-by: Marc-André Lureau <a6f2b960a4aca61381fc650a67901b2ac8e83e6d@redhat.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler