ASoC: wcd934x: Remove some unnecessary NULL checks

ASoC: wcd934x: Remove some unnecessary NULL checks

Clang warns:

../sound/soc/codecs/wcd934x.c:1886:11: warning: address of array
'wcd->rx_chs' will always evaluate to 'true' [-Wpointer-bool-conversion]
        if (wcd->rx_chs) {
        ~~  ~~~~~^~~~~~
../sound/soc/codecs/wcd934x.c:1894:11: warning: address of array
'wcd->tx_chs' will always evaluate to 'true' [-Wpointer-bool-conversion]
        if (wcd->tx_chs) {
        ~~  ~~~~~^~~~~~
2 warnings generated.

Arrays that are in the middle of a struct are never NULL so they don't
need a check like this.

Fixes: a61f3b4f476e ("ASoC: wcd934x: add support to wcd9340/wcd9341 codec")
Link: https://github.com/ClangBuiltLinux/linux/issues/854
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lore.kernel.org/r/20200204060143.23393-1-natechancellor@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>