net: ipa: always inline ipa_aggr_granularity_val()

net: ipa: always inline ipa_aggr_granularity_val()

It isn't required, but all callers of ipa_aggr_granularity_val()
pass a constant value (IPA_AGGR_GRANULARITY) as the usec argument.
Two of those callers are in ipa_validate_build(), with the result
being passed to BUILD_BUG_ON().

Evidently the "sparc64-linux-gcc" compiler (at least) doesn't always
inline ipa_aggr_granularity_val(), so the result of the function is
not constant at compile time, and that leads to build errors.

Define the function with the __always_inline attribute to avoid the
errors.  We can see by inspection that the value passed is never
zero, so we can just remove its WARN_ON() call.

Fixes: 5bc5588466a1f ("net: ipa: use WARN_ON() rather than assertions")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20210811135948.2634264-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>