trusty: Fix return value of trusty_init()
trusty: Fix return value of trusty_init()

The value used to signal failure is 0. It is needed to return a different
value on success.

Change-Id: I2186aa7dfbfc825bfe7b3d5ae3c4de7af10ee44f
Signed-off-by: Antonio Nino Diaz <5c24ff39be768bf31f4deee44042a11772cfd02a@arm.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware