util/build-id: check dlpi_name before strstr call
util/build-id: check dlpi_name before strstr call

According to dl_iterate_phdr man page first object visited is the
main program where dlpi_name is an empty string. This fixes segfault
on Android when using build-id as identifier.

Fixes: d4fa083e11f ("util: Add utility build-id code.")
Signed-off-by: Tapani Pälli <cdcb67a5e49297de94340ca09f25994bd5e7f762@intel.com>
Reviewed-by: Plamena Manolova <6e3d0a3190b3ecb5aa3b51200dd755290989ee5d@intel.com>
Reviewed-by: Emil Velikov <f20878473f414da183da19ee25c8722cc1d711e4@collabora.com>
Reviewed-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler