power_supply: bq2415x_charger: Fix coding style issues

This patch fixes the following issues reported by checkpatch.pl:
- use -EINVAL instead of -ENOSYS, to fix warning message:
  "ENOSYS means 'invalid syscall nr' and nothing else"
- remove unnecessary log message
- split lines whose length is greater than 80 characters
- if an arm statement uses braces, add braces to the other arms of the
  respective statement, too
- match alignment with open parenthesis

Signed-off-by: Anda-Maria Nicolae <anda-maria.nicolae@intel.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>