Remove broken assertion in console_putc()
Andrew Thoelke authored
The assertion in console_putc() would trigger a recursion that
exhausts the stack and eventually aborts.

This patch replaces the assertion with an error return if the
console has not been initialized yet.

Fixes ARM-software/tf-issues#208

Change-Id: I95f736ff215d69655eb5ba7ceac70dc1409d986a
0695dc49