mwifiex: Clean up some err and dbg messages

The error message if 'pci_set_consistent_dma_mask()' fails is misleading.
The function call uses 32 bits, but the error message reports 64.

Moreover, according to the comment above 'dma_set_mask_and_coherent()'
definition, such an error can never happen.

So, simplify code, axe the misleading message and use
'dma_set_mask_and_coherent()' instead of 'dma_set_mask()' +
'dma_set_coherent_mask()'

While at it, make some clean-up:
   - add # when reporting allocated length to be consistent between
     functions
   - s/consistent/coherent/
   - s/unsigned int/u32/ to be consistent between functions
   - align some code

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200819071853.113185-1-christophe.jaillet@wanadoo.fr