powerpc: Fix bad NULL pointer check in udbg_uart_getc_poll()
We have some code in udbg_uart_getc_poll() that tries to protect
against a NULL udbg_uart_in, but gets it all wrong.
Found with the LLVM static analyzer (scan-build).
Fixes: 309257484cc1 ("powerpc: Cleanup udbg_16550 and add support for LPC PIO-only UARTs") Signed-off-by: Anton Blanchard <anton@samba.org>
[mpe: Add some newlines for readability while we're here] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>